-©•^1734^ 

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Goodwin,  Harold 


fVacVlcal  economics  in  distriba- 


ion  with  +heir  effect  on  the  commer- 


cial polica  of  a central  station  com- 


pan^. 


jReturn  this  book  on  or  before  the 
/Latest  Date  stamped  below. 

Theft,  mutilation,  and  underlining  of  books 


are  reasons  for  disciplinary  action  and  may 
result  in  dismissal  from  the  University. 
University  of  Illinois  Library 

APR  1965 

1 

1 

! 

i 

L161— 0-1096 

Digitized  by  the  Internet  Archive 
in  2015 


https://archive.org/details/practicaleconomiOOgood 


'O  DOLLARS  PER  YEAR 


TWENTY  CENTS  PER  COPY 


Published  Monthly  By 

m.  XVII.,  No.  12  General  Electric  Company’s  Publication  Bureau  DEC.,  1914 

Schenectady,  New  York 


ON  THE  CHARLOTTESVILLE  fis  ALBERMARLE  RAILWAY.  LIBRARY  OF 
THE  UNIVERSITY  OF  VIRGINIA  IN  BACKGROUND 


GENERAL  ELECTRIC 
. REVIEW 


Single-Phase  Electric 
Railways 

By 

EDWIN  AUSTIN 

Member  of  the  Staff  of  “The  Engineer”  London 

CONTENTS 

Chapter  1 — The  Single-Phase  System.  II — The  London,  Brighton  and 
South  Coast  Railway.  The  Midland  Railway.  Ill — The  Midi  Railway. 

IV —  The  Blankanese-Hamburg-Ohlsdorf  Railway.  The  Dessau-Bitterfeld 
Railway.  The  Murnua-Oberammergau  Railway.  The  Mittelwald  Railway. 

V —  The  St.  Polten-Mariazell  Railway.  VI — The  Martigny-Orsieres  Railway. 
The  Valle-Maggia  Railway.  The  Rhaetian  Railway.  The  Lotschberg-Simplon 
Railway.  VII — The  Rotterdam-Schevenningen  Railway.  VIII — The  Thams- 
havn-Lokken  Railway.  The  Rjukan  Railway.  IX— The  Swedish  State  Rail- 
ways. X — The  Parma  Single-Phase  Tramways.  XI — The  New  York,  New 
Haven  and  Hartford  Railway.  The  New  York,  Westchester  and  Boston 
Railway.  The  Spokane  and  Inland  Empire  Railway.  The  Rock  Island  and 
Southern  Railway.  The  Hoosac  Tunnel  Railway.  The  St.  Clair  Tunnel  Rail- 
way. 

Devoted  to  exact  and  careful  descriptions  of  complete  rail- 
ways and  portions  of  main  line  railways  electrified  on  the  single- 
phase system,  of  which  there  are  two  in  England  and  a great 
number  in  Europe  and  six  in  the  United  States. 


308  Pagts  8x1 1 346  Illuslrations 


Cloth,  Net  $5.00 


Electrical  Traction  and 
Transmission  Engineering 

By  Prof,  SannM  Sheldon,  A.M.,  Ph.D., 
D.Sc.,  and  Erich  Hausmann,E.E.,M.S. 
CONTENTS 

Determination  of  the  Number  and  Size  of 
Cars  for  an  Urban  Road.  Tractive  Effort 
Required  for  Car  Propulsion.  Types  and  Per- 
formance Curves  of  Motors.  Speed  Curves. 
Railway  Motor  Control.  Energy  Consump- 
tion. The  Distribution  System.  Substations. 
Transmission  Lines.  Steam  and  Hydraulic 
Power  Stations. 

317  Pages  53^x8  In.  127  Ulus.  Net  $2.50 

Electric  Railways 

Theoretically  and  Practically  Treated 
By  SIDNEY  W.  ASHE,  B.S.,  E.E. 
Vol.  I - - - Rolling  Stock 

By  Sidney  W.  Ashe  and  J.  D.  Keiley 
Contents — 290  pages 
Chapter  I — Units — Curve  Plotting — Intsru- 
ments.  II — Analysis  of  Train  Performance. 
Ill — Train  Recording  and  Indicating  Instru- 
ments. IV — Direct  Current  Series  Railway 
Motor.  V — Alternating  Current  Single-Phase 
Motors.  VI — Types  of  Control  and  Their 
Operation.  VII — Car  Bodies.  Vlll — Trucks. 
IX — Brakes  and  Braking.  X — Electric  Loco- 
motive. XI — Electrical  Measurements. 

Vol.  II — Engineering  Preliminaries  and 
Direct  Current  Sub-Stations 
By  Sidney  W.  Ashe 
Contents — 288  Pages 
Chapter  1 — Preliminary  Considerations.  II  — 
Determination  of  Required  Motor  Capacity. 
Ill — Motor  Capacity  (continued).  IV — Sched- 
ules and  Load  Diagrams.  V — Power  House 
and  Substation  Location.  VI — Rotary  Con- 
verter Substations.  VII — The  Rotary  Con- 
verters. VIII — The  Transformer.  IX — 

Insulating  Oils.  X — Auxiliary  Substation 
Apparatus. 

5x7  illustrateJ  Net  $2.50  each 


Public  Utilities 

Their  Cost  New  and  Depreciation, 
by  HAMMOND  V,  HAYES,  Ph.D., 
Consulting  Engineer 

CONTENTS 

Property  Valuations— General  Considerations.  Replace- 
ment Costs  of  Physical  Property.  Determination  of  Replace- 
ment Cost.  Value  as  Going  Concern.  Values  of  Good  Will 
and  Franchises.  Original  Cost.  Commercial  Value.  The 
Worth  of  Service  to  the  Consumer.  Reserves  for  Deprecia- 
tion. Life  of  Plant.  Depreciation.  Fair  Present  Value — 
Rates.  Fair  Present  Value — Condemnation  Sale.  General 
Consideration  Relative  to  the  Regulation  of  Public  Utility 
Undertakings. 

m Pages  6*9  Cloth  Nel%im 


Engineering  Valuation  of 
Public  Utilities  and  Factories 

By  HORATIO  A.  FOSTER 

Author  of  “Foster’s  Electrical  Engineer’s  Pocketbook” 
CONTENTS 

Value:  Commercial,  Earning,  Physical,  Intangible,  etc. 
Purposes  of  Valuation.  Instructions  for  Valuation.  Forms 
for  Use  in  Appraisals.  Valuation  of  Various  Properties. 
Cost  of  Valuing  a Property.  Value  of  Good  Will,  Going 
Concern.  Going  Value.  Depreciation.  Renewals.  Amor- 
tization. Depreciation  Funds.  Appreciation.  Franchise 
Values.  Capitalization.  Control  of  Public  Utilities.  List 
of  Public  Service  Commissions.  Court  Decisions. 


350  Pages  6*9  Many  Forms 


Net  $3.00 


HAVE  YOU  A COPY  OF  FOSTER’S  HANDBOOK? 


D.  VAN  NOSTRAND  COMPANY 

Publishers  and  Bookseliers 


X 


25  PARK  PLACE 


NEW  YORK 


c.  1<  ’ 

Co  - 

- 1 

GENERAL  ELECTRIC  REVIEW 


HALL  STACKS- 

I 


The  Edison-Equipped  Electric  Truck 


is  the  ultimate  solution  of  the  most  important 
problem  now  confronting  the  Warehouse  and 
Storage  Business,  i.e. : Transportation. 


Why  Edison  Storage  Batteries? 

Because  Edison  Nickel-Iron- Alkaline  Storage  Batteries 
have  the  following  advantages  in  this  kind  of  service: 

1.  They  may  be  “boosted”  at  very  high  rales  and  charged  sufficiently  in 

a short  time  to  meet  emergency  conditions. 

2.  They  are  everlastingly  on  the  job  and  require  no  expert  attention  in 

the  garage  or  on  the  road. 

3.  They  may  be  left  idle  or  worked  for  months  on  very  small  daily  mile- 

age without  injury  or  extra  care. 

4.  They  are  guaranteed  to  be  capable  of  developing  100  per  cent  of  rated 

capacity  during  four  full  years,  thereby  eliminating  all  risk  on  the 
purchaser’s  part  that  the  profits  of  the  road  will  be  spent  on  repairs 
or  renewals. 

ECONOMY  plus  RELIABILITY  plus  PERMANENCE 


The  Warehouse  Business  is  a fertile  field  for  the  Central 
Station  and  Electric  Truck  Manufacturer.  We  have  a Co- 
operative Campaign  we  would  like  to  discuss  with  you. 

Edison  Storage  Battery  Co. 


164  Lakeside  Ave. 
Orange,  N.  J. 


II 


GENERAL  ELECTRIC  REVIEW 


Motor  Driven  Auxiliaries 


In  many  modern  central  stations,  particularly  where  economizers  are  used,  the  heat 
balance  requires  some  or  all  of  the  auxiliaries  to  be  motor  driven.  A particularly 
attractive  combination  of  Thyssen  Entrainment  Air  and  Hot  Well  Pumps  with  direct 
connected  motor  is  shown  in  the 
illustration;  this  being  suitable  for 
operation  in  conjunction  with  surface 
condenser  for  high  vacuum  turbine 
requirements. 


A Thyssen  Patent  Air  Pump  is  here 
shown  with  the  top  cover  lifted,  and 
consists  of  two  centrifugal  water 
impellers  delivering  water  through 
entrainment  nozzles  and  producing 
vacua  closely  approximating  the 
theoretical. 


99%  OF  THEORETICAL  VACUUM 


SIMPLE  RUGGED  RELIABLE 

Surface,  Jet  and  Barometric  Condensers,  Water  Cooling  Towers,  Closed  Feed  Water  Heaters. 

C.  H.  WHEELER  MFC.  CO.,  PHILADELPHIA,  PA. 

BRANCHES:  New  York  Chicago  Boston  Cleveland  Charlotte  Pittsburgh  Cincinnati  San  Francisco 


GENERAL  ELECTRIC  REVIEW 


III 


IV 


GENERAL  ELECTRIC  REVIEW 


o 


''We  think  the  chain  equipment  is  one  of 
the  best  things  that  has  ever  been  put  onto 
the  direct  drive  individual  motor  equipped 
printing  press, '' 


Speaking  further  regarding  the  chain  drive  we  had  put 
onto  one  of  his  presses,  this  printer  says: 

“We  wish  you  would  have  your  representative  call  on  the  writer 
within  the  near  future  and  take  up  the  proposition  of  equipping  all  of 
our  machines  with  these  chains.  We  find  that  on  this  one  press  that  is 
equipped  with  your  chain  that  we  get  the  same  number  of  impressions 
per  hour  with  two  buttons  less  on  the  electric  controller  and  it  takes 
from  five  to  six  amperes  less  of  electricity  to  drive  the  machine  than  it 
did  with  the  old  belt  equipment.” 


Speaking  of  a motor-to-lineshaft  drive,  another  firm 
writes  us: 

“The  chain  has  given  us  excellent  satisfaction  and  has  paid  for  it- 
self many  times  over,  and  we  intend  to  install  them  at  various  places 
in  the  future.” 


These  and  many  similar  letters  from  our  customers  show  the  uni- 
versal satisfaction  given  by  MORSE  Silent  Chain  Drives.  They 
would  surely  represent  your  sentiments  also. 

You  simply  can’t  beat  MORSE  Silent  Chain  Drives  for  use  in 
connection  with  electric  motors,  because  they  are  positive,  like  gearing, 
and  flexible  like  belting,  yet  more  efficient  than  either. 

They  save  you  power,  protect  the  motor  from  shocks  and  jars  and 
cost  little  to  maintain,  some  drives  now  operating  in  their  twelfth  year 
without  repairs  of  any  kind  having  been  made. 

For  a short  time  we  can  offer  special  inducements  on  any 
new  work  you  will  undertake.  Investigate  this  matter 
fully  at  once.  Particulars  free  and  no  obligation  to  buy. 

Ash  for  Publication  No.  12,  also. 


Morse  Chain  Company,  Ithaca,  N.  Y. 

Electrical  Dept.  B-54 


GENERAL  ELECTRIC  REVIEW 


V 


-f'A  E 3 xi JTJ  SxJ  7 xJ  0 jVJ D U 37.£)jN 

ELErlHJCAL  £i'JOJ'j')^SKii  i'i  j'/Mi'lUfx'iCTiJflEfia 
fi  u t;  Ei  y,  Ej^j  0 lx\jN  o. 


The  above  Works  of 

The  British  Thomson-Houston  Co.,  Ltd. 

cover  an  area  of  acres,  they  have  a floor  space  of  800,000  square  feet, 

they  consist  of  72  buildings  of  brick  and  steel  construction,  and  are  equipped 
with  the  most  modern  plant  for  the  manufacture  of  all  kinds  of 

Electrical  Apparatus 

for 

Traction,  Power  and  Lighting 

Head  Office  and  Works:  Rugby,  England.  Registered  and  Export  Offices:  83  Cannon  Street,  London. 

Branch  Works:  Coventry  and  Willesden.  Lamps  and  Wiring  Supplies:  77  Upper  Thames  Street,  London. 

BRANCH  OFFICES: 

Birmingham  Cardiff  Dublin  Glasgow  Leeds  London 

Manchester  Middlesbrough  Newcastle  Sheffield  Swansea 


FOREIGN  REPRESENTATIVES: 


ARGENTINE — Buxton  Cassini  & Co.,  Buenos  Aires. 

AUSTRALIA — Australian  General  Electric  Co.,  Melbourne 
& Sydney.  Unbehaun  & Johnstone,  Adelaide.  Engineer- 
ing Supply  Co.  Ltd.,  Brisbane.  Chas.  Atkins  & Co.,  Ltd., 
Perth. 

BRAZIL — Cia  General  Electric  do  Brazil,  Rio  de  Janeiro. 
CHILI  AND  PERU — W.  R.  Grace  & Co..  Santiago  and 
Lima. 

CHINA — Andersen,  Meyer  & Co.,  Shanghai. 

COLOMBIA — Wesselhoeft  & Wisner,  Barranquilla. 

CUBA — Zaldo  & Martinez.  Havana. 


INDIA — The  British  Thomson-Houston  Co.,  Ltd.,  Calcutta. 
Turner  Hoare  & Co.,  Bombay. 

JAPAN — The  British  Thomson-Houston  Co.,  Ltd.,  Yoko- 
hama. Bagnali  & Hilles,  Yokohama.  Mitsui  & Co.,  Tokyo 
and  Osaka. 

MEXICO — The  Mexican  General  Electric  Co.,  Mexico. 

NEW  ZEALAND — The  National  Electrical  and  Engineering 
Co.,  Ltd.,  Auckland,  Dunedin.  Wellington.  Christchurch 
and  Invercargill. 

SOUTH  AFRICA — The  South  African  General  Electric  Co.. 
Johannesburg,  Durban  and  Capetown.  Johnson  & 
Fletcher.  Bulawayo  and  Salisbury. 


VI 


GENERAL  ELECTRIC  REVIEW 


Compact  Induction  Motors 


Mounting  of  a Horizontal  Induction  Motor 


To  reduce  the  motor  length 
10  to  20  per  cent,  use 

BALL  BEARINGS. 

Save  floor  space  and  aisle 
room. 

Note  in  the  mounting 
arrangement  shown,  the 
short  length  taken  up  by 
the  ball  bearings.  Note  also 
the  liberal  lubricant  cham- 
bers— compactness  is  gain- 
ed without  sacrificing 
mechanical  strength  or 
electrical  efficiency. 

For  other  mountings  and  applications 
send  for  bulletin  No.  16-G. 


SKPHALL  BEARING  CD. 

50  CHURCH  ST.  NEW  YORK 


90%  EFFICIENCY 

FROM 

SMITH  TURBINES 

r In  ■ 

Recent  tests  of  a number  of  Smith  l urbines 

-ft  j -f  ii|  ^ ’'ffl 

have  again  proven  their  superiority  over  all 

others.  These  tests  show  efficiencies  of 

from  8o%  to  over  90%  at  part  gate. 

The  engraving  represents  one  of  five  units 

each  of  17,000  horse  power  at  514  r.p.m. 

flV 

under  600  foot  head  furnished  the  Georgia 

. V ■ ’■ 

Power  Co. 

! 

Turbines  furnished  for  heads  from  5 feet  to 

650  feet.  Also  Head  Gate  Hoists,  Steel 

Pipe,  Trash  Racks,  etc. 

. 'M 

-X;  uotfoiTv^^ 

SEND  FOR  BULLETIN  G 

S.  Morgan  Smith  Co.,  York,  Pa. 

Branch  Offices: 

644  American  Trust  Bldg.,  Chicago,  111.,  and  176  Federal  St.,  Boston.  Mass. 

GENERAL  ELECTRIC  REVIEW 


VII 


You  need 


the  new  ENGINEER’S  EDITION  of  the 


TRANSMISSION 

LINE 

CALCULATOR 


Simple  as  a 
slide  rule 


Rapid  and 
reliable 


What  is  it? 


A handsome  morocco  bound  volume,  834 
inches  square,  containing  two  complete  charts, 
each  with  a revolving  transparent  disk, 
together  with  explicit  directions  for  their  use. 


What  will  it  do? 

It  will  calculate  in  TWO  MINUTES  both 
the  per  cent  voltage  drop  and  power  loss  in 
ANY  circuit  up  to  70,000  volts,  with  results 
guaranteed  accurate  within  one-fifth  of  one 
per  cent. 


Who  is  it  for? 

Designing,  operating  and  consulting  engi- 
neers, managers,  superintendents,  wiring  con- 
tractors and  students. 

How  can  it  be  obtained? 

Send  me  your  check  or  money  order  for 
^5.00,  and  I will  forward  you  by  return  mail 
a copy  for  examination.  If  it  is  not  com- 
pletely satisfactory  you  may  return  it  within 
five  days  and  I will  refund  your  money. 

Order  your  copy  today! 
ROBERT  W.  ADAMS,  E.  E. 

180  TABER  AVENUE 

PROVIDENCE  - - - R.  I. 


Safety  LAST 


Although  SAFETY  FIRST 
is  the  general  outcry,  we 
have  headed  this  ad  SAFETY 
LAST,  owing  to  our  belie j 
that  SAFETY  LAST  is  bet- 
ter than  SAFETY  not  at  all. 

Considering  that  the  majority  of  users  of 
the  Holbrook  Hide  Faced  Hammers  and 
Raw  Hide  Mallets  have  found  in  their  use 
SAFETY  LAST,  because  if  what  they  tell 
us  is  true,  they  have  used  most  every  de- 
scription of  a hammer  or  mallet,  which  they 
considered  practical  for  electric  and  copper 
workers,  finally  finding  that  the  raw  hide 
is  far  superior,  not  only  from  an  economic 
basis,  but  also  producing  an  article  super- 
ior to  that  which  they  have  formerly  been 
able  to  make. 


The  raw  hide  surface,  although  soft  enough 
not  to  bruise  the  article  on  which  they  are 
working,  is  hard  enough  to  get  the  desired 
results  from  the  contact  of  the  blow.  If 
these  essentials  are  true,  they  having  tried 
out  various  hammers  or  mallets  construct- 
ed of  other  materials,  and  have  at  last 
adopted  the  use  of  our  raw  hide  goods, 
which  by  their  continued  use  proves  to  us 
that  they  have  found 

Safety  LAST 


WE  WOULD  BE  VERY  GLAD  TO  FURNISH 
DESCJUPTIVE  LITERATURE  WITH  PRICES 
ON  REQUEST. 


Holbrook  Raw  Hide 
Company 

Manufacturers  Providence,  R.  I. 


VIII 


GENERAL  ELECTRIC  REVIEW 


3EJ2 


'.'''it  


mm 


San  Francisco  Municipal  Building 

Wired  with  G-E  Wire  and  Cable 

About  go  miles  of  G-E  Wire  and  Cable  will  be  used  in  the  new  San  Francisco  Municipal 
Building. 

When  completed,  this  will  be  one  of  the  largest  and  finest  municipal  buildings  in  the 
world.  The  illustration  showing  the  building  during  construction,  gives  some  idea  of  its  great 
size  and  handsome  appearance. 

G-E  Wires  and  Cables  are  used  in  the  largest  and  highest  buildings  in  the  world,  as  well 
as  on  the  world’s  greatest  engineering  accomplishment,  the  Panama  Canal. 

General  Electric  Company 

Li  St  of  Sales  Offices  Immediately  Following  Reading  Pages  * 


5192 


GENERAL  ELECTRIC  REVIEW 


IX 


Getting  the  Utmost  Return  from 
Invested  Capital 

Capital  and  labor  conditions  make  efficiency  imperative.  Every  machine  in  a factory, 
every  foot  of  its  floor  space,  every  employee  must  yield  a maximum  return  on  the  investment. 

One  device  or  method  will  save  at  this  point,  another  at  that,  but  electric  power  properly 
applied  through  a G-E  motor  will  save  at  many  points.  In  manufacturing  processes  using 
electric  power,  this  motor.  Industry’s  Master  Workman,  is  also  a great  power  economizer. 

A G-E  motor  can  be  applied  to  drive  each  of  your  machines  at  a maximum  productive 
speed,  even  though  this  speed  varies  for  each  second  of  the  machine’s  operation. 

A G-E  motor  on  each  of  your  machines  allows  the  best  use  of  floor  space,  making  every 
machine  to  which  it  is  applied  independent  of  line-shafting  and  belts. 

A G-E  motor  on  each  of  your  machines,  when  driven  by  purchased  power,  stops  the  power 
bill  whenever  a machine  is  shut  down. 

G-E  motors  can  be  connected  to  a curve-drawing  meter  which  will  record  when  each 
machine  is  started  or  stopped  as  well  as  show  the  amount  of  power  consumed  at  any  moment. 
This  graphic  record  forms  excellent  means  of  discovering  efficient  employees. 

Our  engineers  will  be  pleased  to  study  local  conditions  and  suggest  suitable  electric  equip- 
ment. Write  our  nearest  office. 

General  Electric  Company 

List  of  Sales  Offices  on  Page  Immediately  Following  Reading  Pages 


5252 


X 


GENERAL  ELECTRIC  REVIEW 


G-E  Switchboards  Made  of 


MONSON  SLATE 


This  slate  is  supplied  true  to  dimen- 
sions and  with  a fine  finish.  It  stands  a 
high  insulation  test,  is  strong  and  tough 
but  drills  readily  and  takes  a beautiful 
black  oil  finish  which  costs  practically 
nothing. 

IT  NEEDS  NO  PAINT. 


Portiand-Monson  Slate  Company 

Office,  Portland,  Maine  Quarries,  Monson,  Maine 


GENERAL  ELECTRIC  REVIEW 


XI 


99%  Vacuum  with  The 


A WHEELER  TURBO-AIR  PUMP  recently  tested  showed  the 
^ ^ following  results  with  hurling  water  at  70°: 


100%  vacuum  on  a closed  air  suction. 

99-7%  with  5 cubic  feet  of  free  air  per  minute. 
99.4%  with  10  cubic  feet  of  free  air  per  minute. 
And  99%  with  20  cubic  feet  of  free  air  per  minute. 

Consider  These  Figures 

The  norrrial  air  leakage  of  a large  turbine 
and  condenser  is  only  5 to  10  cubic  feet  of  free 
air  per  minute,  which  the  pump  will  handle  at 
vacuums  above  99%. 

This  means  that  you  can  maintain  at  the 
turbine  exhaust,  vacuums  of  283^  to  29  inches  in 
the  Summer  and  29^^  inches  and  higher  in  the 
Winter,  depending  upon  the  amount  of  circulating 
water  pumped. 


If  interested  in  Turbo- Air  Pumps,  ask  for  our  new  Bulletin  111;  in  Surface  Condensers,  ask 
for  our  new  Bulletin  106-A;  in  High  Vacuum  Jet  Condensers,  Bulletin 
107;  in  Cooling  Towers,  Bulletins  104  and  109. 


WHEELER 

Condenser  and  Engineering  Co. 

CARTERET  110  The  Pioneer  American  Condenser  Builder  NEW  JERSEY 


XII 


GENERAL  ELECTRIC  REVIEW 


THE  GRAND  CENTRAL  TERMINAL 
HOT  WATER  HEATING  SYSTEM 

is  supplied  by  these  four  14-inch  sin- 
gle stage  motor-driven  turbine  type 

ALBERGER 

CENTRIFUGAL  PUMPS 


Alberger  pumps  are  used  in  connection 
with  many  other  forced  circulating  systems 
including  the  Senate  Office  Building,  Wash- 
ington, D.  C.,  Biltmore  Hotel,  New  York, 

Crouse-Hinds  Company,  Syracuse,  and  the 
National  Museum,  Washington,  D.  C. 

WRITE  FOR  CATALOGUE  E. 

ALBERGER  PUMP  & CONDENSER  COMPANY 

140  CEDAR  STREET,  NEW  YORK 

Chicago  Pittsburgh  St.  Louis  Boston  Atlanta  New  Orleans  San  Francisco 


General  Electric  Review 


A MONTHLY  MAGAZINE  FOR  ENGINEERS 


Manager,  M.  P,  RICE 


Editor,  JOHN  R,  HEWETT 


Associate  Editor.  B.  M.  EOFF 
Assistant  Editor,  E.  C,  SANDERS 


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Entered  as  second-class  matter,  March  26:  1912,  at  the  post-office  at  Schenectbdy,  N.  Y.,  under  the  Act  of  March,  1879. 


VOL.  XVII. , No.  12 


Copyright  1914 
by  General  Electric  Company 


December,  1914 


CONTENTS 

Frontispiece 

Editorial:  The  Paths  of  Progress 

Workmen’s  Compensation 

By  James  O.  Carr 

Practical  Economies  in  Distribution  with  Their  Effect  on  the  Commercial  Policy  of  a 

Central  Station  Company 

By  Harold  Goodwin,  Jr. 


Page 

1150 

1151 

1152 


1159 


The  Successful  Operation  of  a Telephone  System  Paralleling  High  Tension  Power  Lines  . 1175 

By  Charles  E.  Bennett 

The  Ventilation  of  Allegheny  Summit  Tunnel,  Virginian  Railway 1182 

By  F.  F.  Harrington 


Electric  Fields 1186 

By  F.  W.  Peek 

Some  Notes  on  Bus  and  Switch  Compartments  for  Power  Stations 1188 

By  Emil  Bern 


Practical  Experience  in  the  Operation  of  Electrical  Machinery 1193 

Transformer  Leads  Reversed;  Importance  of  Equalizer;  Sparking  by  Load  Changes; 
Reversed  Field  Coils;  Ridging  of  Commutator;  Lamps  Flickering 

By  E.  C.  Parham 

Recent  Views  on  Matter  and  Energy 1197 

The  Atomic  Theory  of  Matter,  Part  IV 

By  Dr.  Saul  Dushman 

The  Electrification  of  Cane-Sugar  Factories 1204 

By  a.  I.  M.  WiNETRAUB 


Notes  on  the  Use  cf  Thermo-Electric  Apparatus  in  High  Frequency  Systems,  Part  II 

By  August  Hund 

Application  of  Power  Apparatus  to  Railway  Signaling,  Part  III  . . . 7 

By  H.  M.  Jacobs 

From  the  Consulting  Engineering  Department  of  the  General  Electric  Company 
Question  and  Answer  Section 


1210 

1214 

1229 

1230 


Illustrating  the  Article  in  this  Issue  on  the  Application  of  Power  Apparatus  to  Railway  Signaling,  by  Mr.  H.  M.  Jacobs 


THE  PATHS  OF  PROGRESS 

In  this  issue  we  conclude  a series  of  articles 
by  Dr.  Saul  Dushman  entitled  “Recent 
Views  on  Matter  and  Energy.’’  All  of  our 
readers  who  have  read  these  contributions 
must  have  been  struck  by  the  boldness  of 
many  of  the  speculative  theories  that  have 
recently  been  propounded,  as  well  as  by  the 
fact  that  we  seem  to  be  on  the  verge  of  great 
developments  in  the  realm  of  scientific 
thought. 

The  ultimate  constitution  of  matter  has 
been  the  plaything  of  profound  thinkers  for 
generations  and  the  origin  of  energy  has  been 
no  less  a subject  for  speculative  theorizing, 
but  it  has  been  left  to  the  scientific  minds  of 
this  generation  to  attempt  to  propound  a 
monistic  theory  to  account  for  all  natural 
phenomena.  The  atomic  theory  originally 
propounded  to  account  for  the  mysteries  of 
the  structure  of  matter  was  developed  into 
an  electron  theory  to  explain  electrical  phe- 
nomena, and  now,  as  a product  of  modern 
scientific  thought,  we  have  the  quantum 
theory  which  is  an  atomic  theory  of  energy. 
Thus  it  seems  likely  that  we  shall  ultimately 
not  only  fully  develop,  but  we  may  prove  by 
patient  research  and  experimental  work,  a 
common  theory  for  both  energy  and  matter 
which  may  be  broad  enough  to  include  all 
natural  phenomena.  Should  this  be  accom- 
plished it  is  highly  probable  that  all  natural 
phenomena  will  be  found  to  be  governed  by 
a few  simple  laws,  and  that  the  complexity 
of  many  of  our  scientific  theories  in  the  past 
has  been  caused  by  a lack  of  knowledge  of 
the  simple  laws  that  govern  the  movements 
and  “habits”  of  the  ultimate  “something” 
of  which  both  energy  and  matter  are  born. 

Such  a simplification  of  theories  would 
undoubtedly  lead  to  great  progress  in  scien- 
tific discovery  and  ultimately  to  enormous 
industrial  developments  in  a multitude  of 
different  directions,  and  it  is  for  this  reason 
that  all  engineers  and  professional  men  in 
general  should  try  to  follow  the  trend  of 
modern  scientific  thought.  The  series  of 


articles  referred  to  were  written  with  the 
idea  of  giving  a general  understanding,  in 
simple  language,  of  some  modern  scientific 
speculations  that  may  ultimately  have  a 
far-reaching  industrial  influence.  We  believe 
that  there  is  too  generally  a tendency  to 
consider  all  higher  scientific  reasoning  to  be 
beyond  so  simple  an  interpretation  that  the 
ordinary  lay  mind  can  derive  any  benefit 
following  it.  In  reality  this  is  very  far  from 
the  truth.  While  it  is  true  that  it  takes  a 
great  mind  to  translate  scientific  thought  into 
simple  terms,  it  is  also  true  that  many  men 
have  devoted  much  time  to  this  task. 

Scientific  developments  and  discoveries 
have  been  almost  entirely  derived  in  the 
first  place  from  speculative  imaginations. 
All  theories  must  be  imagined  before  they 
can  be  propounded,  tested,  and  proved  or 
disproved;  indeed,  speculative  imagination 
can  almost  be  said  to  be  the  root  of  all 
progress.  Those  who  take  no  trouble  to 
familiarize  themselves  with  the  speculative 
imaginings  of  modern  scientific  minds  are, 
we  believe  losing  much  that  would  lead  to 
valuable  inspirations  that  might  be  applied 
to  their  own  work,  no  matter  what  its  nature. 
In  these  days  of  specialists  there  is  too 
marked  a tendency  to  think  a general  under- 
standing of  the  activities  of  others  as  of 
little  value. 

Imagination  is  the  seed  of  all  originality 
and  in  these  days  of  competition  there  is 
more  and  more  need  of  original  thought  in 
all  industrial  activities.  The  type  of  reason- 
ing displayed  in  developing  scientific"  theories^ 
by  such  men  as  Kelvin,  Planck,  etc.,  might 
well  be  imitated  in  many  walks  of  engineer- 
ing and  business  life.  The  imagination  should 
be  given  full  range  and  any  theory  arrived 
at  should  be  tested  till  some  are  found  that 
will  bear  the  fruit  desired.  We  believe  that 
a careful  study  of  the  work  accomplished 
by  those  great  minds  engaged  in  scientific 
research  might  give  great  inspiration  and  lead 
to  an  added  efficiency  in  the  reasoning  powers 
of  all  men. 


1152 


GENERAL  ELECTRIC  REVIEW 


WORKMEN’S  COMPENSATION 

By  James  O.  Carr 

Law  Department,  General  Electric  Company 

Workmen’s  compensation  laws  are  one  of  the  products  of  modern  conditions,  and  the  laws  throughout 
the  union  are  many  and  varied,  no  less  than  twenty-four  states  having  adopted  laws  compensating  workmen 
for  industrial  accidents.  No  one  claims  that  these  laws  are  perfect  and  it  is  likely  that  many  modifications, 
based  on  experience  gained  from  their  working,  will  be  adopted  from  time  to  time.  The  author  deals  in  a 
very  interesting  manner  with  many  phases  of  the  different  laws  already  in  force  and  discusses  the  pros  and 
cons  of  their  practical  working. — Editor. 


One  of  the  most  remarkable  reform  move- 
ments in  the  industrial  world  of  the  United 
States  in  recent  years  is  that  which  has  had  for 
its  object  the  enactment  of  laws  requiring  the 
payment  of  compensation  to  workmen  who  are 
injured  in  the  course  of  their  employment. 
The  theory  upon  which  this  movement  has 
proceeded  is  that  the  workman  should  be 
compensated  for  disabilities  resulting  from 
industrial  accidents  regardless  of  the  question 
of  fault,  and  that  the  financial  burdens  of  such 
accidents  should  be  borne  by  the  industry  in 
general  rather  than  by  the  workers  alone. 

While  this  principle  has  been  in  force  in 
some  of  the  European  countries  for  many 
years  yet  it  is  only  within  the  past  five  years 
that  the  matter  has  been  taken  up  actively  in 
the  United  States. 

A law  was  enacted  in  the  State  of  Massa- 
chusetts in  1907  permitting  employer  and 
employee  to  agree  on  a plan  of  compensation 
and  the  State  of  Montana  passed  a compensa- 
tion act  relating  to  the  coal  industry  in  1909, 
yet  neither  seemed  to  accomplish  the  desired 
result  and  little  or  no  progress  was  made 
thereunder.  It  really  received  its  initial 
impetus  in  1909  when  a commission  was 
appointed  by  the  Legislature  of  the  State  of 
New  York  to  investigate  the  whole  subject. 

During  the  year  1910,  two  compensation 
laws  were  passed  in  the  State  of  New  York, 
one  elective  and  one  compulsory,  but  early  in 
the  year  1911  the  compulsory  law  was 
declared  unconstitutional  by  the  Court  of 
Appeals  of  the  State  of  New  York,  upon  the 
ground  that  it  took  the  property  of  employers 
without  due  process  of  law.  During  the  year 
1911,  compensation  laws  were  passed  in  the 
States  of  California,  Illinois,  Kansas,  Massa- 
chusetts, Nevada,  New  Hampshire,  New 
Jersey,  Ohio,  Washington  and  Wisconsin, 
some  of  which  were  compulsory  and  some 
elective. 

Since  that  time,  compensation  laws  have 
been  passed  by  other  states  so  that  the  prin- 
ciple is  now  in  force  or  soon  will  be  in  twenty- 
four  different  states.  One  of  the  last  states 


to  enact  a workmen’s  compensation  law  was 
the  great  State  of  New  York,  where  the  law 
was  passed  in  the  month  of  December,  1913. 
That  law  is  in  many  respects  the  most  liberal 
to  the  workman  and  the  most  burdensome  to 
the  employer  of  any  compensation  law  passed 
by  the  various  states.  It  was  passed  more  or 
less  hurriedly  with  the  idea  that  the  practice 
of  compensating  workmen  for  injuries  sus- 
tained through  industrial  accidents  should 
be  commenced  at  once  and  that  an  actual  trial 
of  the  law  would  show  wherein  it  ought  to  be 
amended  so  as  to  improve  it  for  the  benefit 
of  all  concerned.  It  has  been  in  actual  opera- 
tion since  July  1,  1914,  and  it  is  already 
evident  that  many  changes  are  necessary  to 
make  the  law  more  workable. 

Many  of  the  most  prominent  labor  leaders 
in  the  country  have  said  that  the  present 
workmen’s  compensation  law  of  the  State  of 
New  York  is  the  best  compensation  law  ever 
passed  in  this  country.  That  this  is  so  from 
the  standpoint  of  the  workman  is  undoubtedly 
true.  Many  of  the  employers  feel  that  the 
law  ought  to  be  less  burdensome  to  them 
than  it  is.  However,  this  will  undoubtedly  be 
worked  out  satisfactorily  in  time. 

In  most  of  the  states  the  law  is  elective, 
that  is,  the  employer  and  the  employee  may 
elect  to  accept  the  ptovisions  of  the  law  or  not 
just  as  they  choose.  In  the  case  of  the 
employer  who  elects  not  to  comply  with  the 
provisions  of  the  law,  however,  all  his  defenses 
are  taken  away  in  case  the  workman  sues  him 
for  damages  for  personal  injuries,  so  that  the 
employer  is  almost  compelled  to  accept  the 
provisions  of  the  law  rather  than  to  attempt 
to  defend  negligence  actions  and  be  subjected 
to  the  large  verdicts  which  would  certainly 
be  rendered  against  him.  If  the  employee 
elects  not  to  accept  the  provisions  of  the  law, 
he  is  relegated  to  the  same  rights  which  he  had 
at  the  time  the  new  law  went  into  effect.  In 
the  opinion  of  many  who  are  conversant  with 
these  compensation  laws,  the  workman  should 
only  have  the  rights  which  existed  at  common 
law  if  he  refuses  to  accept  the  provisions  of  the 


WORKMEN’S  COMPENSATION 


1153 


compensation  law,  the  idea  being  to  compel 
both  parties  to  abide  by  the  principle  of  com- 
pulsory compensation. 

In  some  states  the  eompensation  law  is 
compulsory,  that  is,  both  employer  and 
employee  must  abide  by  the  requirements  of 
the  law  and  the  employer  must  pay  the  com- 
pensation therein  provided. 

The  elective  laws  were  passed  by  many  of 
the  states  in  order  to  avoid,  if  possible,  any 
question  as  to  the  constitutionality  of  the  law 
such  as  was  raised  at  the  time  the  first  com- 
pulsory law  was  passed  by  the  State  of  New 
York.  The  new  law  in  many  of  the  states 
provides  that  all  workmen  shall  come  under 
its  provisions  except  farm  and  domestic  labor. 
In  other  states,  the  laws  are  so  framed  as  to 
cover  only  those  workmen  who  are  engaged  in 
so-called  hazardous  employments.  Where 
this  has  been  done,  however,  some  means 
have  been  found  to  include  nearly  all  work- 
men. This  very  feature  is  one  of  the  objec- 
tions to  the  New  York  law  because  it  is  uncer- 
tain what  workmen  are  eovered  by  the  law 
and  what  ones  it  does  not  cover.  How  much 
better  it  is  for  a workman  to  be  under  the 
protection  of  the  compensation  laws  can 
readily  be  seen.  As  soon  as  he  is  injured, 
he  is,  in  many  of  the  states,  entitled  to  medi- 
cal attendance  for  a period  of  from  two  weeks 
to  three  months,  at  the  expense  of  the  em- 
ployer. This  also  covers  hospital  treatment, 
medicine  and  other  requisites.  All  of  this  is 
to  be  provided  by  the  employer. 

If  the  injury  causes  temporary  disability  of 
more  than  one  week,  in  some  states,  and  more 
than  two  weeks  in  others,  which  is  called  the 
waiting  period,  the  workman  is  paid  a certain 
percentage  of  his  average  weekly  wages, 
ranging  from  50  per  cent  in  some  states  to 
66%  per  cent  in  others,  so  long  as  the  dis- 
ability continues,  subject  to  certain  limitations 
as  to  length  of  disability  and  amount  paid. 

In  some  states,  in  the  event  that  an  accident 
eauses  total  permanent  disability  to  the  work- 
man, he  is  paid  the  weekly  percentage  of  his 
earnings  for  periods  of  time  ranging  from  six 
years  to  the  remainder  of  his  natural  life. 

If  the  workman  sustains  a permanent 
partial  disability,  such  as  the  loss  of  a finger, 
eye,  hand,  arm  or  foot,  he  is  then  paid  a 
certain  stipulated  amount  per  week  for  a 
certain  period  to  compensate  him  for  the  loss 
sustained.  In  some  states  he  is  also  paid 
weekly  eompensation  during  the  time  of 
disability  caused  by  the  permanent  injury ; but 
the  most  satisfactory  way  seems  to  be  to  pay  a 
certain  fixed  amount  which  is  considered  suffi- 


cient to  compensate  for  the  loss,  and  this  is 
provided  for  in  the  laws  of  most  of  the  states. 

In  some  states,  the  workman  is  compen- 
sated for  the  loss  of  earning  power  due  to 
injury.  This  is  likely  to  prove  quite  trouble- 
some as  time  goes  on  and  will  lead  to  compli- 
cations, as  some  of  the  Workmen’s  Compen- 
sation Commissions  of  the  various  states  seem 
inclined  to  hold  that  if  a workman  goes  back  to 
work  and  takes  a different  job  which  pays  less 
money  than  he  earned  at  time  of  injury,  he  is 
therefore  entitled  to  compensation  for  loss 
of  earning  power. 

If  an  injury  proves  fatal,  then  the  widow, 
children  or  other  dependents  are  paid  a certain 
percentage  of  the  weekly  wages  of  the 
deceased  workm;an.  In  some  cases  this  com- 
pensation is  paid  for  the  life  of  the  widow  if  she 
does  not  re-marry,  and  in  others,  for  a certain 
number  of  years  and  not  to  exceed  a certain 
amount.  The  compensation  to  be  paid  to 
children  usually  ceases  when  they  reach  the 
age  of  eighteen.  In  addition,  many  of  the 
states  require  the  employer  to  pay  a certain 
amount  for  funeral  expenses. 

The  compensation  is  paid  to  the  workman 
in  various  ways.  In  New  York,  for  instance, 
the  employer  pays  the  money  to  the  Work- 
men’s Compensation  Commission  and  it  in 
turn  pays  the  injured  workman  or  his  depen- 
dents. This  plan  is  unwieldy  and  cumber- 
some and  is  not  nearly  as  expeditious  as  the 
practice  in  many  other  states  where  the 
employer  makes  arrangements  to  pay  the 
workman  direct  the  amount  provided  by  law 
pursuant  to  an  agreement  made  between  the 
parties  which  is  subject  to  the  approval  of  the 
Commission.  In  some  states  where  the  prin- 
ciple of  state  insurance  has  been  put  into 
effeet,  the  compensation  is  paid  direct  to  the 
workman  from  the  premiums  paid  in  by  the 
employers.  In  some  states,  the  compensation 
must  be  secured  to  the  workmen  either 
through  the  medium  of  insurance  in  stock  or 
mutual  companies,  through  the  medium  of  a 
state  fund  or,  if  the  employer  can  give  satis- 
factory proof  of  his  financial  ability  to  pay  com- 
pensation to  his  employees,  he  may  be  per- 
mitted to  carry  his  own  insurance  upon  giving 
a satisfactory  bond  or  depositing  sufficient 
security  to  guarantee  the  payment  of  the  com- 
pensation. Most  employers  carry  insurance 
in  either  stoek  or  mutual  companies.  Only 
the  employers  having  a large  number  of 
employees  can  afford  to  carry  their  own 
insurance. 

Various  methods  are  adopted  for  handling 
disputes  between  the  interested  parties  so  that 


1154 


GENERAL  ELECTRIC  REVIEW 


the  workman  may  receive  the  compensation 
to  which  he  is  entitled  as  soon  as  possible 
after  an  accident. 

As  time  goes  on,  many  developments  will 
take  place  in  connection  with  the  practical 
working  out  of  these  laws  and  we  shall  have 
a far  better  knowledge  of  them  and  their 
beneficial  effects  or  otherwise  five  years 
hence. 

That  the  general  plan  is  sound  and  will 
work  out  to  the  interest  of  all  concerned  is 
probably  conceded  by  all  who  have  given 
the  matter  thoughtful  consideration.  The 
necessity  for  such  legislation  has  been  more 
or  less  forced  upon  us  by  the  course  of  human 
events  and  by  the  many  changes  and  develop- 
ments in  the  method  of  carrying  on  modern 
industry. 

Prior  to  1880,  the  handling  of  business  on  a 
large  scale  and  through  the  medium  of  great 
corporations  was  practically  unknown,  except 
perhaps  with  respect  to  railroads  and  the 
manufacturing  interests  in  New  England. 
Subsequent  to  that  time,  however,  by  reason 
of  the  great  improvements  in  machinery,  it 
became  possible  to  have  done  by  machinery 
the  work  which  had  formerly  been  done  by  the 
individual  workman,  and  in  many  instances 
the  workman  was  displaced  by  machinery. 
The  result  of  this  has  been  that  in  every 
industry  the  production  has  been  marvelous- 
ly increased  and  this  feature  has  been  largely 
instrumental  in  developing  the  great  manu- 
facturing industries  in  the  United  States. 
While  enormous  strides  were  being  made  in 
the  manufacturing  field,  there  was  also  a 
great  increase  in  the  number  of  industrial 
accidents  due  to  the  greater  use  of  machinery 
and  the  hazard  incident  thereto.  As  a con- 
sequence, the  burden  on  society  was  greatly 
increased  because  of  the  fact  that  the  work- 
man was  seldom  compensated  for  disabilities 
due  to  accidents  occurring  in  the  course  of  his 
employment. 

In  former  years,  when  manufacturing  was 
carried  on  in  a small  way  by  the  individual 
employer,  he  usually  knew  most  of  his 
employees  and  took  more  or  less  of  a personal 
interest  in  them  and  in  their  welfare.  This 
resulted  in  a friendly  feeling  between  the 
employer  and  the  employee  and  there  then 
existed  a bond  of  human  sympathy  between 
them.  It  is  also  a fact  that  in  those  days  the 
labor  union  was  almost  unknown  and  had 
little  or  no  influence  upon  manufacturing 
operations. 

With  the  development  of  the  industry 
through  the  medium  of  machinery  there  came 


another  development,  that  of  the  labor  union> 
which  today  has  almost  a predominating 
influence  in  all  parts  of  the  country  where 
large  bodies  of  workmen  are  employed.  With 
these  developments  and  the  creation  and 
growth  of  the  large  corporations  the  human 
element  was  lost  sight  of  in  many  ways.  The 
workman  was  looked  upon  more  and  more  as  a 
machine  rather  than  an  individual.  This,  of 
course,  was  not  true  in  every  case,  but  it  is 
true  and  must  of  necessity  be  so  where  thous- 
ands of  workmen  are  employed  in  one  industry 
since  those  in  charge  of  the  industry  are 
absolutely  unable  to  be  in  personal  touch  with 
all  of  the  employees.  This  is  also  true  where 
the  labor  unions  predominate,  because  the 
members  of  the  labor  organizations  seem  to 
prefer  to  deal  with  their  employers  through 
the  medium  of  their  organizations  and  this 
has  a tendency  to  eliminate  the  personal 
element. 

In  the  days  of  small  industries,  when  a 
workman  was  in  trouble  or  was  incapacitated 
through  injury,  he  was,  in  many  instances, 
looked  after  in  some  way  by  his  employer  who 
attempted  to  relieve  him  and  his  family  from 
the  loss  which  he  was  bound  to  sustain.  It  is 
not  to  be  understood  that  this  was  so  in  every 
instance  but  it  was  in  many  cases.  At  the 
same  time  the  employer  who  was  engrossed  in 
accumulating  wealth  undoubtedly  very  often 
overlooked  the  misfortune  of  his  employee 
and  was  inclined  to  rely  upon  his  legal  rights 
in  the  event  that  any  claim  was  made  upon 
him  for  compensation. 

The  common  law  governing  the  relations  of 
employers  and  employees  in  connection  with 
injuries  sustained  during  the  course  of  employ- 
ment was  such  that  the  employer  was  seldom 
held  legally  responsible  for  injuries  which 
happened  to  the  workman  in  the  day’s  work. 
The  only  way  in  which  the  workman  could 
recover  money  damages  from  his  employer 
was  by  proving  that  the  employer  was  negli- 
gent and  that  he  did  not  fulfill  the  duty  which 
he  owed  the  employee.  It  can  well  be  realized 
how  difficult  it  was  for  the  employee  to  sus- 
tain this  burden  when  he  was  obliged  to  prove 
that  he  himself  was  in  no  way  negligent  and 
that  his  actions  did  not  contribute  to  the 
accident;  that  he  did  not  understand  the  risk 
and  did  not  assume  it  and  that  the  accident 
was  not  due  to  the  neligence  of  some  other 
employee  engaged  on  the  work.  Prior  to  the 
enactment  of  the  Employers  Liability  Laws, 
in  many  states  even  the  superintendent  in 
charge  of  the  work  was  held  in  many  instances 
to  be  a co-employee,  so  that  if  for  any  reason 


WORKMEN’S  COMPENSATION 


1155 


the  accident  happened  through  his  negligence 
the  employee  could  not  recover. 

The  law  in  these  respects  being  so  harsh 
upon  the  employee  and  the  burden  on  society 
caused  by  industrial  accidents  having  increased 
so  rapidly,  it  became  more  and  more  apparent 
that  there  must  be  some  enlargement  made  of 
the  rights  of  the  employee  to  recover  for 
accidents  sustained  in  the  course  of  his 
employment.  As  a result  many  of  the  states 
have  from  time  to  time  passed  so-called 
employers  liability  laws,  placing  a much 
greater  burden  upon  the  employer  and  reliev- 
ing the  employee  in  many  ways.  Up  to  the 
year  1912  these  laws  had  become  so  drastic 
so  far  as  the  employer  was  concerned  that  it 
was  more  and  more  difficult  for  him  to  escape 
the  payment  of  damages  to  injured  work- 
men regardless  of  how  the  accident  might 
have  happened.  This  situation  came  about 
in  many  respects  through  the  work  of  unscrupu- 
lous lawyers  who  became  so  skilled  in  negli- 
gence litigation  that  they  could  almost 
always  find  some  means  of  making  the  case  a 
question  of  fact  which  the  Courts  have  held 
required  the  submission  of  the  case  to  a jury. 
Within  the  past  ten  years  the  submission  of 
such  a case  to  a jury  almost  invariably  result- 
ed in  a verdict  for  the  plaintiff  against  the 
defendant.  If  the  defendant  was  a corpora- 
tion it  was  almost  a foregone  conclusion  that 
the  verdict  would  be  a substantial  one  and 
that  it  would  eventually  be  sustained  by  the 
Appellate  Courts.  Juries  in  the  past  five 
years  have  seemed  to  lose  their  reason  and 
judgment  when  called  upon  to  render  ver- 
dicts in  cases  of  this  character.  The  amounts 
awarded  by  them  have  been  astounding  and 
unreasonable  beyond  any  question.  Passion 
and  prejudice  have  undoubtedly  prevailed 
in  a great  many  cases  of  this  character  and 
have  tended  to  influence  the  verdict.  The 
defendant,  however,  has  found  it  almost 
impossible  to  demonstrate  that  such  was  the 
case.  The  slogan  has  been:  “The  corpora- 

tion is  rich;  it  can  stand  it.  Let’s  give  the 
poor  fellow  a good  substantial  verdict.’’ 

By  reason  of  this  situation  the  employer 
who  has  been  looking  into  the  future  has 
tried  to  establish  for  his  own  welfare  as  well 
as  that  of  his  employees,  a system  of  com- 
pensation which  would  to  some  extent  relieve 
the  employees  from  the  burden  of  industrial 
accident  and  that  the  employers  have  suc- 
ceeded admirably  in  many  cases  is  a well- 
known  fact.  That  this  should  be  done  from 
a social  standpoint  need  not  be  demonstrated. 
That  it  should  be  done  from  a business  stand- 


point also  requires  no  demonstration.  The 
employee  himself  was  made  to  realize  that  it 
was  for  his  interest  to  co-operate  with  his  em- 
ployer along  these  lines  when  it  became  more 
and  more  apparent  that  the  lawyers  who  handle 
negligence  litigation  were  in  almost  every 
instance  merely  exploiting  the  injured  work- 
man for  the  purpose  of  getting  the  substantial 
fee  which  they  would  obtain  in  the  event  of  the 
litigation  being  successful.  The  speculative 
feature  of  this  class  of  litigation  had  a tendency 
to  make  the  plaintiff  as  well  as  his  lawyers 
disregard  the  truth  in  many  instances,  the  sole 
object  being  to  endeavor  to  obtain  a verdict 
against  the  employer. 

Many  employers  have  for  years  been 
carrying  on  their  own  systems  of  compensa- 
tion for  injured  and  killed  workmen  and  their 
dependents,  and  have  been  successful  in  their 
efforts  in  this  direction  and  have  succeeded  in 
reducing  the  annoyance  and  expense  incident 
to  negligence  litigation  to  a minimum  and 
have  thereby  been  able  to  increase  the  com- 
pensation and  relief  to  the  injured  employee. 
Particularly  is  this  true  in  respect  to  the 
employer  who  has  handled  his  own  insurance 
rather  than  by  having  insurance  companies 
protect  him  through  the  medium  of  casualty 
insurance. 

Undoubtedly  one  of  the  greatest  incentives 
to  the  enactment  of  workmen’s  compensation 
laws  in  the  various  states  has  been  the 
methods  adopted  by  casualty  companies  in 
conducting  their  business  and  in  adjusting 
claims  made  by  employees  for  injuries  sus- 
tained by  them.  The  attitude  of  the  insur- 
ance companies  until  very  recent  years  has 
been  that  they  would  not  pay  anything  to  the 
injured  workman  if  it  was  possible  to  avoid  it, 
preferring  to  rely  upon  their  legal  defenses  in 
case  the  workman  saw  fit  to  bring  a suit. 
Whenever  an  accident  happened  the  insurance 
company  intervened  between  the  employer 
and  the  employee  and  the  employee  was 
obliged  to  conduct  his  negotiations,  if  any, 
with  the  insurance  company.  Naturally  the 
ordinary  workman  is  not  versed  in  matters  of 
this  character  and  he  was  at  a tremendous 
disadvantage  when  attempting  to  do  business 
with  the  representatives  of  the  insurance 
companies.  As  a result  he  was  imposed  upon; 
he  was  unable  to  clearly  understand  his  legal 
rights,  and  was  made  to  understand  that 
before  he  could  hope  to  recover  anything  he 
would  be  obliged  to  go  through  a protracted 
litigation  which  might  extend  over  a period  of 
years  and  in  the  end  it  was  possible  and  per- 
haps probable  that  he  would  be  unsuccessful. 


1156 


GENERAL  ELECTRIC  REVIEW 


in  which  event  he  would  recover  nothing. 
During  all  the  time  that  this  litigation  might 
continue  he  would  have  the  worry  and  annoy- 
ance of  it  and  nothing  to  compensate  him  for 
his  injury,  which  in  many  instances  was 
serious ; so  that  the  insurance  companies  by  use 
of  such  arguments  were  in  most  instances  able 
to  effect  a settlement  for  a small  amount  and 
get  the  case  disposed  of.  It  is  significant  that 
the  records  show  that  prior  to  the  time  when 
compensation  laws  were  first  enacted  in  this 
country  the  amount  disbursed  by  insurance 
companies  in  the  way  of  payment  of  com- 
pensation to  injured  employees  was  about 
30  per  cent  of  the  total  premiums,  the  balance 
being  used  by  the  insurance  companies  for  the 
payment  of  their  expenses  and  dividends  to 
their  stockholders.  Of  the  30  per  cent  prob- 
ably a large  amount  was  paid  over  by  employ- 
ees to  lawyers  and  others  for  assistance 
rendered  by  them.  It  can  readily  be  seen  that 
the  real  purpose  for  which  insurance  was  taken 
out  was  not  to  insure  the  payment  of  compensa- 
tion to  the  injured  workmen  when  the  accident 
was  due  to  the  fault  of  the  employer,  but  rather 
to  relieve  the  emoloyer  from  making  any  pay- 
ment whatsoever  and  as  a result  the  workman 
received  a small  percentage  of  the  amount  to 
which  he  was  really  entitled  and  in  addition 
considerable  feeling  was  engendered  between 
him  and  the  employer.  It  was  apparent  to  the 
manufacturers  who  where  able  to  look  ahead 
that  this  state  of  affairs,  coupled  with  the 
expense  and  annoyance  incident  to  the  harass- 
ing negligence  litigation,  could  not  continue 
much  longer  and  that  some  remedy  should  be 
found  which  would  make  both  of  these  things 
entirely  unnecessary,  and  in  addition  enable 
both  employer  and  his  employee  to  work 
more  in  harmony  with  each  other,  and  afford 
the  man  who  was  injured  at  his  work  a partial 
recompensation  for  the  loss  which  he  should 
sustain.  The  workmen  were  also  beginning 
to  think  along  the  same  lines. 

While  the  employers  and  employees  may 
both  claim  the  credit  for  workmen’s  compen- 
sation legislation,  yet  regardless  of  the 
question  as  to  whom  the  credit  belongs  it  may 
safely  be  said  that  it  is  one  of  the  greatest 
steps  in  promoting  social  welfare  that  has 
occurred  in  modern  times.  It  may  well  be 
termed:  “The  movement  to  conserve  human 
life  and  health  through  the  medium  of  legis- 
lative enactment.’’  As  times  goes  on  both  the 
employer  and  the  employee  will  wonder  why 
the  great  waste  of  human  life  and  health 
which  we  have  endured  up  to  very  recent 
years  was  permitted  to  go  on  unchecked  when 


it  was  possible  to  remedy  the  difficulty  so 
readily.  It  will  also  be  found  after  these  laws 
have  been  enforced  for  a short  time  that 
neither  the  employer  nor  the  employee  would 
be  willing  to  go  back  to  the  old  condition  of 
things  under  any  consideration.  That  it  may 
be  classed  as  paternal  legislation  is  in  one 
sense  true,  but  on  the  other  hand  it  is  agreed 
that  paternal  legislation  that  brings  desired 
results  to  all  parties  interested  alike  is  the 
best  kind  of  legislation  that  can  be  enacted. 
There  can  be  no  ground  for  arguing  that  such 
a law  is  unjust  and  inequitable,  so  far  as  the 
principle  is  concerned.  In  the  years  gone  by 
the  machine  in  the  shop  when  out  of  order  was 
shut  down  and  promptly  repaired  so  that  it 
might  be  again  put  in  use  for  the  purpose  for 
which  it  was  designed  and  thereby  enable  the 
employer  to  make  use  of  it  In  turning  out  his 
product.  In  the  same  way  the  horse  that  was 
used  for  hauling  the  freight  and  other  material 
around  the  plant  when  taken  sick  was  prompt- 
ly attended  to  by  the  veterinary.  He  was  fed 
and  cared  for,  and  every  effort  made  to  put 
him  in  good  condition  so  that  he  could  again 
resume  his  work.  To  be  sure  no  wages  were 
paid  to  the  horse  but  yet  as  compensation  for 
the  food  and  care  which  he  received  he  per- 
formed a certain  amount  of  work  for  the 
employer.  That  this  condition  of  affairs 
should  have  been  overlooked  for  so  many 
years  and  these  principles  not  applied  to  the 
human  machine  seems  almost  startling  in 
the  light  of  present  day  developments.  Why 
is  it  that  the  human  machine  did  not  receive 
equally  as  good  care  and  treatment  as  the 
others?  Was  it  because  of  selfishness  or 
neglect  or  failure  to  consider  the  true  merits  of 
the  situation?  The  answer  undoubtedly  is 
that  when  the  human  machine  became  out  of 
order  for  any  reason  it  could  promptly  be 
replaced  by  another  without  any  trouble  or 
apparent  expense,  and  for  that  reason  the  man 
who  was  injured  in  employment  was  displaced, 
for  the  time  being  in  any  event,  by  another 
workman  who  was  prepared  to  take  up  his 
work,  and  if  the  former  employee  had  been  so 
disabled  as  to  be  unable  to  resume  his  employ- 
ment then  the  new  one  could  remain  on 
permanently.  In  the  case  of  the  horse  it 
would  cost  a substantial  sum  of  money  to 
replace  him  even  temporarily,  whereas  with 
the  human  being  it  cost  nothing,  so  that  the 
action  taken  may  properly  be  said  to  have 
depended  entirely  upon  the  question  of  cost. 
Nowadays  the  employer  is  finding  out  that  it 
is  money  well  invested  to  keep  the  human 
machine  in  proper  working  order  and  con- 


WORKMEN’S  COMPENvSATION 


1157 


dition.  The  benefits  derived  from  his  efforts 
in  this  direction  are  manifold.  It  is  seen  not 
only  in  the  workman  himself  but  the  benefit 
redounds  to  his  wife  and  children  and  to  the 
public  in  general  which  is  relieved  from  any 
apparent  burden  so  far  as  he  is  concerned. 
If  a man  is  in  good  physical  condition  he  can 
naturally  do  more  work  and  do  it  better  than 
the  man  who  is  ailing  and  unfit  for  the  employ- 
ment in  which  he  is  engaged.  The  more  and 
the  better  production  the  manufacturer  is 
able  to  put  out  the  more  business  he  does,  the 
larger  his  income,  and  presumably  the  greater 
his  profits.  The  saving  to  the  community  in 
general,  by  reason  of  the  enactment  of  laws 
regarding  compensation  of  workmen  who  are 
injured  in  the  course  of  their  employment,  will 
more  than  compensate  for  any  additional  ex- 
pense to  which  the  state  may  be  put  in  admin- 
istering such  laws.  Heretofore  a large  portion 
of  the  time  of  our  courts  has  been  devoted 
almost  exclusively  to  the  conduct  of  neg- 
ligence litigation  arising  out  of  accidents  to 
employees.  In  fact  the  calendars  in  some  of 
the  courts  in  the  larger  cities  have  been 
almost  entirely  filled  with  these  negligence 
actions.  Without  question  the  work  of  the 
courts  in  such  a state  as  New  York  will  be  so 
materially  decreased  by  the  disappearance  of 
this  class  of  litigation  that  many  of  the  judges 
will  have  time  on  their  hands  and  some 
of  them  could  be  dispensed  with.  When 
the  enormous  expense  that  is  attendant 
upon  the  operation  of  the  courts  is  realized 
it  will  be  seen  at  a glance  that  a great  saving 
is  to  be  effected.  In  addition  to  that,  the 
workman  who  is  seriously  injured  is  not  going 
to  be  a burden  upon  himself  and  his  family 
, and  upon  society  in  general.  He  is  not  going  to 
be  made  to  feel  that  he  is  dependent  on  charity 
: for  his  existence.  He  is  still  going  to  be  able 
to  hold  his  head  up  among  other  men,  knowing 
that  so  long  as  he  is  deprived  of  his  ability 
to  work  by  reason  of  the  injury  sustained  in 
the  course  of  his  employment  he  is  going 
to  receive  compensation  to  assist  him  to  a 
I considerable  extent  in  caring  for  his  family 
during  the  time  of  his  disability.  This  feeling 
I of  self  respect  which  the  workman  will  have 
is  in  itself  worth  a good  deal  and  will  tend  to 
make  him  in  most  instances  a better  citizen. 

I The  burden  of  compensating  employees  will 
be  borne  by  the  industry  and  when  it  is  of 
sufficient  amount  to  be  at  all  appreciable  it 
will  be  added  to  the  cost  of  the  production,  and 
the  consumer,  which  is  the  public,  will  pay 
for  it.  In  this  way  society  in  general  pays  the 
expense  as  it  really  does  in  everything  else 


ultimately.  The  workman  who  is  compen- 
sated while  injured  will,  by  being  able  to 
receive  enough  to  keep  his  family  from  want, 
also  be  able  to  keep  his  children  in  school 
and  thereby  confer  an  untold  benefit  upon 
them.  They  will  not  of  necessity  be  obliged 
to  start  in  work  when  the  wage  earner  of  the 
family  is  disabled,  whereas  they  might  be 
obliged  to  do  so  much  before  the  intended 
time  if  there  were  not  other  means  of  support. 
Of  course  it  is  impossible  to  have  legislation 
of  this  character  which  is  not  without  some 
drawbacks  and  subject  to  much  criticism. 
In  many  of  the  states  the  claim  is  made  that 
the  compensation  is  too  liberal  and  too  far- 
reaching  in  that  it  will  be  an  incentive  where 
the  compensation  is  too  high  for  the  injured 
workman  to  remain  out  of  employment  as 
long  as  he  possibly  can.  Of  course  there  may 
be  something  in  this,  particularly  if  the  work- 
man carries  his  own  insurance  either  through 
insurance  companies  or  some  fraternal  organi- 
zation, for  by  taking  such  insurance  benefits  in 
conjunction  with  the  compensation  paid  by 
the  employer  he  may  derive  more  than  the 
sum  which  he  would  receive  when  working 
steadily.  This,  however,  is  a condition  which 
must  be  met.  In  some  states  the  list  of 
dependents  is  carried  to  extremes,  persons 
being  entitled  to  compensation  as  far  remote 
from  the  injured  person  as  grandparents 
and  grandchildren  and  nephews  and  nieces. 
It  is  undoubtedly  true  that  the  schedule  of 
compensation  for  partial  permanent  dis- 
ability seems  in  many  instances  high  but  time 
alone  will  tell  how  burdensome  this  may  be  in 
the  states  where  such  compensation  seems  to 
be  unduly  high.  Fortunately  this  only  per- 
tains to  a class  of  accidents  which  are  fewest 
in  number.  That  an  untold  amount  of  good 
is  going  to  be  accomplished  by  these  laws 
must  be  admitted  without  controversy.  It  is 
going  to  have  a tendency  to  cause  employers 
to  investigate  more  carefully  their  working 
conditions  in  order  that  they  may  ascertain 
wherein  they  may  reduce  the  number  of 
accidents  in  their  factories.  Every  accident 
prevented  means,  theoretically,  so  many 
dollars  earned,  because  by  reducing  the 
number  of  accidents  the  expense  incidental 
thereto  will  also  be  diminished.  An  employer 
will  be  warranted  in  expending  money  for 
the  purpose  of  reducing  the  number  of  acci- 
dents because  it  will  be  found  to  be  an 
excellent  investment.  The  amount  of  stimu- 
lation that  has  occurred  since  the  beginning 
of  the  agitation  for  workmen’s  compensation 
legislation  is  surprising.  Many  large  manu- 


GENERAL  ELECTRIC  REVIEW 


1158 

facturers  have  b66n  and.  now  are  spending 
thousands  of  dollars  in  safeguarding  machinery 
and  doing  other  things  to  decrease  the  hazard 
of  the  employment  and  make  it  safe  for  the 
life,  limb  and  health  of  the  employee.  Natur- 
ally these  things  have  a tendency  to  iniprove 
the  efficiency  of  the  workman  and  his  sur- 
roundings. One  of  the  great  elements  which 
have  been  found  to  have  a very  important 
bearing  upon  industrial  accidents  is  the 
question  of  lighting  and  it  has  been  shown 
that  many  accidents  which  could  well  be 
prevented  have  been  caused  by  failure  to 
properly  light  the  place  where  the  employee 
was  performing  his  work.  It  has  been  found  a 
simple  proposition  in  many  ways  to  place 
these  safeguards  around  the  employee  and 
thereby  reduce  the  possibility  of  accidents 
and  it  is  undoubtedly  due  to  the  fact  that  it 
has  been  so  simple  and  easy  to  do  these  things 
that  they  have  been  left  undone  for  so  long  a 
period  of  time.  In  another  respect,  outside 
of  compensation  for  industrial  accidents,  the 
employee  is  bound  to  derive  a substantial 
benefit.  The  burden  which  the  employers 
have  had  placed  upon  them  has  led  them  to 
take  a much  greater  interest  in  the  welfare  of 
their  employees  and  has  put  them  in  touch 
with  many  conditions  which  were  unknown 
before.  Until  recent  years  no  special  effort 
has  ever  been  made  to  fit  the  work  to  the  man 
but  it  has  usually  been  a case  of  fit  the  man  to 
the  work.  The  requirements  of  the  compen- 
sation laws  have  given  the  employer  a new 
incentive  and  that  is  to  try  to  see  that  he  has 


workmen  physically  able  to  perform  the  work 
for  which  they  are  engaged.  To  this  end 
many  of  the  employers  of  labor  throughout  the  | 
country  have  adopted  the  policy  of  medical  \ 
examination  which  is  believed  will  prove  to  be  | 
of  untold  benefit  to  employer  and  employee  ; 

alike.  It  does  not  mean  that  the  man  who  is 

not  physically  perfect  will  be  shut  out  or  pre- 
vented from  obtaining  employment,  but  it 
does  mean  that  more  care  will  be  used  in  the 
emplovment  of  labor  and  that  an  effort  will 
be  made  to  place  the  man  at  the  kind  of  work 
which  he  is  physically  able  to  do  rather  than 
to  place  him  at  the  kind  of  work  which  he 
thinks  he  wants  to  do  but  for  which  he  does 
not  know  he  is  physically  unfit.  Such  pro- 
cedure is  bound  to  be  beneficial  to  both  parties  . 
because  it  will  tend  to  improve  the  efficiency 
of  the  employee,  thereby  benefitting  the 
manufacturer;  it  will  tend  to  conserve  the 
life  and  health  of  the  employee,  thereby 
enabling  him  to  perform  his  duty  to  society  , 
and  by  lengthening  out  his  life  it  will  extend 
the  period  of  his  usefulness  to  his  family  and 
the  community.  Society  has  much  to  be 
thankful  for  when  we  consider  the  amount  of 
suffering  and  distress  that  is  going  to  be 
saved  by  reason  of  the  enactment  into  law  of 
the  principle  of  compensating  workmen  who 
are  injured  in  the  performance  of  the  work_ 
incident  to  their  employment  and  in  the  , 
years  to  come  the  employers  and  employees 
will  wonder  why  such  a blessing  to  mankind  | 
was  not  brought  into  existence  many  years  ^ 
before. 


PRACTICAL  ECONOMIES  IN  DISTRIBUTION  WITH  THEIR  EFFECT 
ON  THE  COMMERCIAL  POLICY  OF  A CENTRAL  STATION  COMPANY 

DOHERTY  MEDAL  PAPER— 1914 


By  Harold  Goodwin,  Jr.* 

Assistant  Superintendent  Distribution,  The  Philadelphia  Electric  Company 

The  content  of  this  article  is  of  great  practical  value  to  all  those  concerned  in  any  way  with  the  distribution 
- of  electrical  energy  through  overhead  lines  (the,.«e&ditions  existing  in  underground  lines  are  conformable  to 
” the  same  treatment  as  is  used  herein  for  overhead  lines).  This  article  is  meritorious  chiefly  because,  unlike 
others,  its  author  has  studiously  avoided  falling  into  the  error  of  delivering  either  with  an  exposition  based 
only  on  theory  or  a treatise  founded  ^lely  on  practice.  A comparison  of  the  merits  of  the  radial  and  the  tree 
systems  is  made;  load  capacity  data/(5f  the  secondary  distributing  lines  are  given  in  tabular  form;  and  cost  data 
of  line  materials  and  their  erectioij  are  presented,  also  in  tabular  form.  A careful  explanation  of  the  local 
factors  which  have  to  be  considered  in  distribution  problems  and  well-balanced  helpful  advice  supplement  the 
value  that  can  be  derived  from  the  tables.  Through  the  courtesy  of  Current  News  we  have  been  able  to 
publish  this  excellent  article. — Editor. 


INTRODUCTION 

The  technical  press  is  at  present  filled 
with  notes  on  the  cost  of  central  station 
service  showing  at  one  end  of  the  system 
the  present  low  generating  costs  and  at  the 
other  the  almost  fixed  charges  per  customer’s 
service.  ’Twixt  these  there  is  a great  gulf 
fixed  and  labeled  “Distribution  Costs.’’  The 
central  station  man  goes  into  competition 
with  the  isolated  plant  and  finds  his  main 
generating  costs  much  lower,  but  then  he  has 
to  add  “Distribution  Costs’’  that  seem  to 
wither  his  chances  for  the  business.  Mr.  P. 
Junkersfeld,  in  his  report  on  “Distribution” 
to  the  last  (1914)  midwinter  convention  of 
the  A.I.E.E.,  states;  “The  great  importance 
of  the  subject  of  distribution  of  electrical 
energy  is  further  indicated  by  the  fact  that, 
in  the  average  central  station  system  in  a 
large  city,  the  fixed',  charges  and  operating 
expense  of  the  distribution  system  are  nearly 
three  times  the  fixed  charges  and  operating 
expense  of  the  power  house.” 

Most  central  stations  meter  the  output 
of  their  generating  or  substations  and  also 
sum  up  the  total  of  customers’  meter  registra- 
tions and  compare  the  two.  There  is  a dis- 
crepancy of  from  10  to  50  per  cent.  This  is 
put  down  as  distribution  loss;  a little  is 
accounted  for  as  transformer  core  loss  and 
the  remainder  just  entered  mentally  to  the 
discredit  of  the  distribution  engineers. 

Yet  what  is  being  done  to  reduce  these 
costs  and  losses  ? Eminent  engineers  are 
working  to  increase  turbine  and  generator 
efficiencies  if  only  by  half  of  one  per  cent. 
Practically  all  transmission  systems  are  in 
the  hands  of  competent  engineers.  Others 
of  equal  standing  in  their  profession  are 
continually  devising  means,  by  combining 


loads  of  different  characteristics,  by  which 
the  efficiency  of  the  substations  may  be 
raised.  These  same  men  lay  out,  more  or  less 
definitely,  distribution  systems  with  rules  as 
to  voltage  and  phase  of  motors,  grouping 
loads  on  transformers,  maximum  voltage 
drop  from  feeder  end  to  last  transformer,  etc. 
Then  what? 

The  operation  of  the  generating  stations, 
transmission  systems,  and  substations  is  put 
in  the  hands  of  engineers;  complete  meter 
and  instrument  readings  are  continually 
taken  and  the  results  are  checked  up  against 
those  previously  calculated  and  an  efficient 
condition  is  thus  maintained.  But  what  is 
done  for  the  efficiency  of  the  system  beyond 
the  substation  ? The  general  rules  on  voltage, 
phase,  etc.,  are  given  to  a “practical  man” 
who  knows  from  experience  the  “one- 
hundred-and-one  ” mechanical  details  that 
enter  his  problem  and  he  proceeds  to  build 
primary  lines,  hang  transformers,  run  second- 
aries, and  supply  the  current  to  meters 
registering  with  almost  absolute  accuracy 
to  the  fraction  of  a per  cent.  General  voltage 
tests  are  made  and  the  job  is  said  to  be  a 
good  one.  A complaint  may  come  in  and  the 
voltage  being  found  a little  low  a new  trans- 
former is  hung,  or  new  secondaries  are  run 
in  a manner  which  has  caused  no  complaint 
to  the  “practical  man”  at  another  location 
and  is  therefore  to  him  the  proper  thing. 

Some  “practical  men”  have  gone  further 
and  have  investigated  their  transformers  to 
see  that  they  are  properly  loaded  and  have 

^ * The  writer  desires  ,to  take  occasion  to  express  his  apprecia- 
tion of  the  excellent  distribution  work  done  by  the  Aerial  Line 
Department  of  The  Philadelphia  Electric  Company,  which  has 
inspired  this  paper,  though  it  has  been  done  without  the  confi- 
dence of  these  figures.  He  also  wishes  publicly  to  extend  his 
thanks  to  Mr.  William  Foster  for  his  willingness  in  supplying  the 
assumed  figures  on  costs  and  to  Mr.  N.  E.  Funk  and  Mr.  Clarence 
W.  Fisher  for,.their>ssistance  in  the  preparation  of  the  article. 


1160 


GENERAL  ELECTRIC  REVIEW 


thus  shown  a considerable  saving.  This 
showing,  with  the  ability  which  guided  their 
work,  has  qualified  them  for  higher  positions 
which  they  have  assumed.  They  have  then 
written  articles  showing  mostf  beautifull}^  the 
advantages  of  grouping  load  on  transformers 
and  the  advantages  of  diversity  factor  and 
so  forth;  they  have  proceeded  to  the  study  of 
transmission  lines  and  given  us  no  end  of 
valuable  information  and  short  cuts  on  the 
calculation  of  these  problems.  But  what 
have  they  done  to  help  the  man  who  is  still 
struggling  to  determine  whether  he  should 
put  a transformer  in  every  block  with  small 
secondary  wires,  or  only  one  in  every  four 
blocks  with  heavy  secondary  wires? 

At  this  point  the  young  technical  graduate 
has  advanced  his  theories  and  figured  out 
a superb  ( !)  system  with  conductors  tapered 
down  toward  the  end  of  the  secondary, 
giving  what  he  claims  to  be  the  ideal  system 
of  distribution.  Suddenly  a large  load  is  to  be 
added  at  a point  where  his  conductors  have 
been  neatly  tapered  down;  it  is  necessary  to 
renew  them  and  he  comes  to  believe  the 
“practical  man”  is  correct  in  building  with 
the  same  size  conductor  throughout,  so  he 
throws  his  theory  to  the  winds  and  is  lead 
by  the  “practical  man.”  Occasionally  special 
cases  force  themselves  upon  him  and  he  may 
figure  out  what  is  the  economical  arrange- 
ment. 

But  as  yet  no  practical  man  who  has 
acquired  the  theory,  or  theoretical  man  who 
has  learned  the  practice,  has  given  to  his 
fellow  practical  workers  throughout  this 
country  even  the  most  simple  and  funda- 
mental tables  of  capacity  and  economical 
use  of  wires,  except  the  N.E.  Code  rules  on 
the  ampere  capacity  of  various  sized  con- 
ductors. 

The  “Lamp  Committees”  are  now  dis- 
cussing the  question  of  adopting  one  standard 
voltage  lamp  for  a given  system.  Yet  who 
knows  for  alternating  current  systems  in 
general  whether  the  range  in  voltage  on  the 
lamps  is  to  be  arbitrarily  fixed  by  the  com- 
mittee at  a maximum  which  they  consider 
will  still  give  good  service,  or  whether  the 
actual  losses  of  energy  in  the  distribution 
system  supplying  the  lamps  will  not  definitely 
limit  the  range  of  voltage  at  the  different 
services  ? 

It  is  with  this  vast  and  complicated 
unknown  of  DISTRIBUTION  that  this 
paper  will  deal.  First  will  be  submitted  a few 
comments  on  primary  systems  and  a pre- 
liminary set  of  tables  for  guidance  of  the 


practical  man.  Then  a study  of  the  funda- 
mentals of  the  economic  side  of  the  situation 
will  be  made,  pointing  out  the  need  for 
research  and  testing  along  certain  lines. 

Attention  will  be  confined  entirely  to  over- 
head lines  and  detailed  discussion  will  only 
be  given  the  transformer  and  secondary  lines. 
The  methods  used  in  comparing  fixed  with 
operating  charges  are  familiar  and  of  course 
apply  equally  well  to  primary  and  secondary, 
though  the  almost  infinite  complication  of 
the  secondary  problem  is  increased  seven-fold 
when  the  primaries  are  considered  in  con- 
junction with  it.  There  are,  however,  certain 
practical  limitations,  explained  later,  which 
enter  to  exclude  the  primary  from  considera- 
tion and  the  solutions  are  therefore  more 
general  than  would  appear  at  first  sight. 

All  methods  also  apply  to  underground 
construction  and  to  comparison  of  overhead 
and  underground  structures,  though  to  cover 
completely  only  the  subject  in  hand  would 
require  such  a large  volume  that  consideration 
of  these  last  two  subjects  has  been  omitted 
entirely. 

All  figures  on  costs  are  altogether  approxi- 
mate and  are  not  supposed  to  represent  the 
experience  of  any  one  company,  and  are  ’ 
introduced  simply  to  make  the  results  more 
tangible.  It  would,  of  course,  be  possible 
to  work  out  the  whole  problem  with  algebraic  , 
symbols  leaving  it  to  anyone  interested  to 
substitute  true  values  and  solve  for  the  result. 
It  would  also  have  been  possible  to  take  these 
figures  from  “Data”  or  other  handbooks.  ■ 
But  they  are  simply  assumed  and  are  there- 
fore not  open  for  discussion  unless  their 
accuracy  materially  affects  the  conclusion??  ■ 

The  figures  on  maximum  carrying  capacity 
of  wires  are  derived  from  Table  B,  para- 
graph 18  of  the  “N.E.  Code,”  1913  edition. 
All  figures  connected  with  power  and  voltage 
loss  are  based  on  the  familiar  formulae: 

DXWXC 
\ PXE^ 

V = PXB 
where 

A — area  of  conductor  in  circular  mils. 

D = distance  one  way  from  source  to 
receiver. 

W = load  in  watts. 

C = 2400  for  95  per  cent  power-factor, 
single-phase. 

= 3380  for  80  per  cent  power-factor, 
single-phase. 

P = per  cent  power  loss  of  delivered  power. 

E = receiver  volts. 


PRACTICAL  ECONOMIES  IN  DISTRIBUTION 


V = per  cent  voltage  loss. 

B = constant  given  in  following  table  for 
60  cycles: 


No. 'of  Wire 
B.&S. 
Gauge 

Conductor 

Area 

Circular  Mils 

VALU 

95  Per  Cent 
P-F. 

E OF  B 

80  Per  Cent 
P-F. 

6 

26,200 

1.05 

1.00 

4 

41,600 

1.11 

1.10 

2 

66,600 

1.18 

1.26 

0 

106,000 

1.31 

1.49 

00 

133,000 

1.34 

1.66 

000 

168,000 

1.49 

1.95 

0000 

212,000 

1.62 

2.09 

PRIMARY  DISTRIBUTION  SYSTEMS 

There  are  two  generally  accepted  alternat- 
ing current  distribution  systems  which  can 
be  considered  regardless  of  the  cycles,  phase, 
or  voltage  so  long  as  the  latter  is  not  above 
the  generally  accepted  standard  of  2400  volts. 
These  two  systems  are  the"‘-‘Iree ” or  “main 
and  branch’’  system,  and  the  “radial’’  or 
“center  of  distributioin ’ ’ system. 

Fig.  1 shows  the  “center  of  distribution’’ 
f*system  as  submitted  by  Mr.  H.  B.  Gear 
in  Appendix  II,  to  the  report  of  the  Distri- 
bution Committee  to  the  last  (1914)  mid- 
winter convention  of  the  A.I.E.E.  For  this 


Fig.  1.  Radial  System  of  Distribution 


system  very  good  voltage  regulation  is 
claimed  on  account  of  the  radial  feeds  from 
the  centers  A,  B,  and  C.  The  same  writer 
shows  in  another  diagram  that  emergency 
connections  between  the  three  circuits  must 


be  provided  at  points  where  they  come  close 
together.  In  his  concluding  paragraph  he 
states : 

“The  feeder  system  must  be  reinforced 
as  may  be  necessary  from  time  to  time  to 


Fig.  2.  Main  and  Branch  System  of  Distribution 

Ti'cc.  * 

carry  the  added  load.  This  involves  re- 
arrangement of  connections  of  primary  main 
and  many  complicated  ‘ cut-overs  ’ which 
add  to  the  expense  very  materially.’’ 

We  do  not  doubt  this  writer’s  statement. 

Now  contrast  this  first  method  with  the 
“tree’’  or  “main  and  branch’’  system  shown 
in  Fig.  2,  for  covering  the  same  section.  A 
rough  comparison  will  show  that  the  wire 
lengths  from  the  feeding  points  to  the  most 
distant  points  are  not  materially  different 
from  those  in  Fig.  1,  and  therefore  the  regu- 
lation must  be  almost  the  same.  In  fact, 
it  is  difficult  to  see  where  Fig.  1 has  any 
advantage,  so  long  as  there  are  no  diagonal 
streets. 

A comparison  can  also  be  drawn  on  the 
basis  of  continuous  service  which  is  one,  if 
not  the  most  rigid,  requirement  at  the  present 
time.  Suppose  trouble  occurs  and  a man  goes 
out  to  locate  and  repair  it.  In  the  “radial” 
system  he  has  to  go  around  many  corners 
and  look  in  many  places.  On  the  “tree” 
system  he  has  one  straight  main  to  travel 
and  after  clearing  that,  if  necessary,  he  can 
travel  out  any  branch  he  finds  in  trouble, 
moving  quickly  to  the  point  in  question. 

Suppose  the  main  feed  “B”  is  in  trouble 
in  either  system.  See  how  simple  it  is  to 


1162 


GENERAL  ELECTRIC  REVIEW 


“cut-over”  the  load  to  “A”  or  “C”  on  the 
main  street  in  Fig.  2,  while  in  Fig.  1 it  would 
apparently  be  done  in  an  out-of-the-way 
comer. 

Mr.  Gear’s  opinion  has  been  quoted  on 
the  work  necessary  to  introduce  a new  feeder 
in  Fig.  1.  Notice  how  simple  it  is  in  Fig.  2. 
The  breaks  may  be  closed  and  the  main  cut 
into  four  sections  and  the  new  feeder  mn  at 
a minimum  expense. 

In  Fig.  2 there  would  probably  be  another 
main  running  directly  by  the  substation. 
This  would  have  branches  on  the  same  streets 
as  A,  B,  and  C.  These  would  be  mn  to  meet 
each ’other  on  the  same  street  parallel  to  the 
rriciin.  A,  B,  C,  3.nd  in  C3,s6  of  trouble  on  B, 
and  C the  whole  load  could  temporarily  be 
transferred  to  the  mains  nearer  the  sub- 
station. _ 

Consider  also  the  simplicity  of  the  pole 
line  constmetion  in  Fig.  2,  as  compared  to 


the  main  of  112/224  volts  which  allows  for 
a slight  loss  in  the  service  wires  and  house 
wiring,  insuring  110  volts  at  the  lamp  socket. 
The  power  loss  and  voltage  _ loss  are  both 
assumed  at  1 per  cent.  If  it  is  decided  that 
this  is  the  proper  loss  to  allow  for  any  system 
the  values  of  loads  in  the  tables  are  correct; 
if  a different  loss  is  to  be  allowed  the  values 
can  easily  be  multiplied  by  that  per  cent. 

An  attempt  will  be  made  later  to  determine  ; 
what  that  value  is  and  it  should  be  noted  , 
particularly  that  there  is  no  reason  why  it 
should  work  out  to  an  even  per  cent,  indeed 
when  the  tables  have  once  been  multiplied 
it  makes  little  difference  in  their  use  how  ^ 
irregular  the  per  cent  voltage  or  power  loss 

may  have  been.  ' 

Tables  have  been  used  throughout  rather 
than  curves,  because  there  are  so  few  standard  | 
sizes  of  wire  on  any  system  that  it  is  believed  , 
to  be  a more  simple  matter  to  pick  the  | 


- 

K.  — — 

- w — 

g 



A 

< O 

Fig.  3.  Electric  Circuit  with  Uniformly  Distributed  Load 


the  many  irregular  dead  ends  and  corners 

to  be  turned  in  Fig.  1.  _ . 

But  it  is  not  intended  to  discuss  the  primary 
systems  in  this  paper,  so  probably  enough  has 
been  said  to  allow  the  assumption  later  in  the 
calculations  that,  for  all  normal  loads,  the 
primary  should  always  be  present.  The  cost 
of  its  erection  can,  therefore,  in  general  be 
neglected. 


^ LOAD  CAPACITY  OF  SECONDARY 

^ distribution  lines 


As  stated  in  the  introduction,  it  is  proposed 
to  present  a set  of  tables  of  the  capacity  o 
secondary  distribution  systems  for  the  use 
of  the  practical  man.  These  alone  will  not 
show  whether  a given  system  is  economical 
or  not,  but  they  will  show  the  losses  in  any 
system  and  anyone  using  them  may  depend 
on  his  own  judgment  for  determining  the 
allowable  losses  until  such  time  as  the 
calculations  shown  in  the  latter  part  of  this 


article  have  been  made.  ,,n/oon  u 

The  three-wire  nominal  llU/22U^oit 
single-phase  secondary  system  has  been 
assumed  with  an  actual  delivery  voltage  from 


values  from  the  tables  for  a few^  sizes,  rather 
than  from  a curve  covering  all  sizes. 

The  distribution  of  loads  covered  in  the'i 
tables  are  typical; 

First:  Load  concentrated  at  one  end  ot 

secondary  with  transformer  at  opposite  end. 

Second:  Uniformly  distributed  load  witff 

transformer  at  one  end.  ' 

Third:  Uniformly  distributed  load  with;j 

transformer  in  center.  * 

Any  other  loadings  can  be  figured  from  a 
combination  of  these.  All  loads  are  giy^n 
kilowatts.  The  uniformly  distnbuted  load 
tables  have  been  carried  down  to  the  lower 
hundreds  of  feet  merely  to  show  how  enor- 
mously the  capacity  increases  under  these 
conditions  though  it  is  an  impractical  condi- 
tion on  a pole  line  since  services  can  only  be 
tapped  from  the  mains  at  poles,  which  are 
in  the  vicinity  of  100  feet  apart.  -r  . 

It  is  interesting  here  to  note  that  it  the 
lamps  of  various  customers  are  proper!} 
rated  for  the  average  voltage  of  the  secondaip 
supplying  them,  it  makes  no  difference  in  th( 
central  station  revenue  how  great  the  voltag* 
drop,  within  a long  range,  since  the  cun^e  o 


if 


i 


PRACTICAL  ECONOMIES  IN  DISTRIBUTION 


IKD 


watts  to  volts  is  a straight  line  for  a consider- 
able distance  both  sides  of  normal  rating. 
It  does  make  a very  considerable  difference, 
however,  in  the  amount  of  light  received 
and  current  consumed  by  the  first  and  last 
customers,  since  the  lamps  of  the  former  will 
be  burning  above  rating  and  those  of  the 
latter  below  rating. 

The  length  to  be  used  in  calculating  both 
voltage  and  power  loss  with  a uniformly 
distributed  load  is  a point  of  interest.  It  is 
generally  known  that  to  find  the  maximum 
voltage  loss,  half  the  greatest  distance  and 
the  total  load  are  used  in  the  formula. 
However,  it  is  probably  not  so  well  known 
that  to  find  the  total  power  loss  only  one-third 
of  the  total  length  is  used.  It  may  therefore 
be  worth  while  to  derive  the  equations  for 
voltage  drop  and  watts  loss  in  the  uniformly 
loaded  circuit  represented  by  Fig.  3. 

5r  = an  electric  circuit  of  uniform  resist- 
ance. 

S = source,  and  load  is  distributed  uni- 
formly towards  “ T.” 

I = current  at  “ 5.  ” 

Current  at  “ T ” = 0. 

E = potential  difference  between  “S” 
and“r.” 

W = total  power  loss  in  circuit. 

Let 

f = current  at  any  point  “A”  at  a 
distance  “x”  from  “T.” 

Then 

. J 

t~L  X. 

= volts  loss  in  a section  “dx.” 

Let 


Then 


r = resistance  of  circuit  per  unit  length. 


de  = irdx. 


r r 7 rxdx  = ^ T 

Jo  J J c 


xdx. 


But 


7rL2  ^ L 


-Lr  = R. 


Similarly 

= watts  loss  in  a section  “dx.” 

Then 

dw  — i^rdx. 


U 

3 


PrL 

3 ■ 


In  order  to  show  the  method  of  a])])lying 
the  formula  (page  11  GO  of  “Introduction”) 
to  the  following  tables,  calculation  is  here 
made  of  the  capacity  of  500  feet  of  No.  00 
wire  at  224  volts  delivered  with  a power  loss 
of  one  per  cent,  a power  factor  of  80  per  cent, 
and  with  the  load  concentrated  at  the  opposite 
end  from  the  transformer. 

The  formula  as  given  previously  reads: 

nxwxc 

PXE^'  • 

Since  “W”  is  the  unknown  the  formula  is 
transposed  for  use : 

AXPXP 
DXC  ■ 

A = 133,000  circular  mils. 

P=1  per  cent. 

E = 224  volts. 

D = 500  feet. 

C = .3380. 

Then 


W = 


133,000X1  X (224)2 
500X3380 


= 3.9  kilowatts. 


This  value  will  be  found  in  Table  II. 

A similar  calculation  for  1 per  cent  maxi- 
mum voltage  loss  may  be  made. 

This  involves  the  use  of  the  formula : 

V = PXB. 

Since  “P”  is  the  unknown  this  may  be 
transposed : 


But 


U=  1 per  cent. 
P=1.6G  (page  1161). 


P = rh  = 0.602. 

1.66 

_ 133,000  X 0.602  X (224)2 
500X3380 


= 2.4  kilowatts. 


This  value  may  be  found  in  Table  I. 

As  noted  in  the  first  paragraph  these 
tables  are  useful  for  determining  the  loss 
under  any  given  conditions.  Suppose  a 
500-foot,  No.  00  secondary,  similar  to  that 
used  in  the  preceding  calculations  is  carrying 
a load  of  12  kw.  and  it  is  desired  to  know  the 
voltage  drop.  Table  I or  the  foregoing 
calculations  show  a load  of  2.4  kw.  will 
produce  a drop  of  1 per  cent.  Therefore  12 
kw.  will  produce  a drop  of  12  divided  by  2.4, 
or  5 per  cent.  The  actual  voltage  drop  is  then 
5 per  cent  of  224  or  11.2  volts. 

The  values  of  “P”  as  used  in  the  foregoing 
formula  are  shown  in  the  second  column  of 


GENERAL  ELECTRIC  REVIEW 


1164 

Tables  I to  VI.  In  the  third  column  is  shown 
the  maximum  load  the  circuit  will  carry 
without  overheating,  based  on  the  rating  of 
wires  with  other  than  rubber  insulation  m 
Table  B,  paragraph  18  of  the  “N.E.  Code, 
1913  edition. 

COST  DATA  ON  DISTRIBUTION  LINES 
The  following  figures  given  in  Tables  I to 
VI  are  dependent  on  the  fundamental 


electrical  properties  of  wires  and  are  entirely 
independent  of  how  or  when  the  wires  are 
erected  or  the  cost  of  erecting  them.  It  is 
now  proposed  to  consider  the  costs  of  erecting 
wires  and  their  supports  with  a view  to  ascer- 
taining  the  factors  which  need  particular 
attention.  As  stated  in  the  introduction,  the 
figures  have  only  the  most  general  foundation 
in  practice  and  are  merely  assumed 
tabulated  in  order  to  show  the  data  which 


W- 


W 


Table  I 

KILOWATT  CAPACITY  OF  SECONDARY  MAINS 
Load  Concentrated  at  Opposite  End  of  Main  from  Transformer 
Single-Phase;  1 Per  Cent  Maximum  Volts  Loss;  224  Volts  Delivered 


Wire 

Size 

B.&S. 


00 

000 

0000 


0.95 

1.00 

0.90 

0.91 

0.85 

0.79 

0.76 

0.67 

0.74 

0.60 

0.67 

0.51 

0.62 

0.48 


Maximum 

12.5 
! 19.1 

16.1 

26.6 
22.4 

42.6 
35.9 

: 48.0 

40.3 

58.6 

49.3 

69.2 

59.3 


UPPER  FIGURES  KILOWATT  CAPACITY— 95  PER  CENT  P-F. 

LOWER  FIGURES  KILOWATT  CAPACITY— 80  PER  CENT  P-F.  (MOTORS; 


100  j 

200 

300  1 

400  j 

500 

h je> 

1 

5.2 

2.6 

1.7  ] 

1.3  i 

1.0 

3.9 

1.9 

1.3 

1.0 

0.8 

7.8 

3.9 

2.6 

2.0 

1.6 

5.6 

2.7 

1.9 

1.4 

1.1 

11.8 

5.9- 

3.9 

2.9 

2.4 

7.8 

3.9 

2.6 

1.9 

1.6 

ia.8 

8.4'' 

5.6 

4.2 

3.4 

10.5 

5.2 

3.5 

2.6 

2.1 

20.5 

10.3 

6.8 

5.1 

4.1  1 

11.8 

5.9 

3.9 

2.9 

2A 

23.4 

11.7 

7.8 

5.9 

4.7  1 

12.7 

6.3 

4.2 

3.2 

1 2.5 

27.4 

13.7 

9.1 

6.9 

1 5.5 

15.0 

7.5 

5.0 

3.8 

3.0 

Distance  in  Feet 
600 

0.9 
0.7 

1.3 
0.9 
2.0 
1.1 
2.8 
1.7 

3.4 
2.0 
3.9 
2.1 
4.6 

2.5 


700 

0.7 

0.6 

1.1 

0.8 

1.7 

1.1 

2.4 

1.5 

2.9 

1.7 
3.3 

1.8 

3.9 
2.1 


800 

0.6 

0.5 

1.0 

0.7 

1.5 
1.0 
2.1 

1.3 

2.6 

1.5 

2.9 

1.6 

3.4 

1.9 


900 


0.6 

0.4 

0.9 

0.6 

1.3 
0.9 
1.9 
1.2 

2.3 

1.3 

2.6 

1.4 
3.0 
1.7 


1000 


0.5 

0.4 

0.8 

0.6 

1.2 

0.8 

1.7 
1.1 
2.0  ■ 
1.2 

2.3 

1.3 

2.7 
1.5 


Wire 

Size 

B.&S. 


6 

4 

2 

0 

00 

000 

0000 


1.00 

1.00 

1.00 

1.00 

1.00 

1.00 

1.00 

1.00 

1.00 

1.00 

1.00 

1.00 

1.00 

1.00 


Table  II 

KILOWATT  CAPACITY  OF  SECONDARY  MAINS 
Load  Concentrated  at  Opposite  End  of  Main  from  Transformer 
Single-Phase;  1 Per  Cent  Power  Loss;  224  Volts  Delivered 


Maximum 


14.9 

12.5 

19.1 

16.1 

26.6 
22.4 

42.6 

35.9 
48.0 

40.3 

58.6 

49.3 

69.2 

59.3 


l"o"w"e"r  f^'SuL^^  ^;i‘:Xt\^  c^^^ac^ItVIo  P^gR  c^nt^  p-I: 


Distance  in  Feet 


100 

5.5 

3.9 

8.7 
6.1 

13.9 
9.9 

22.0 

15.7 

27.7 

19.7 
35.0 

24.8 
44.2 
31.4 


200 

2.7 

1.9 
4.3- 

3.1 

6.9 

4.9 
11.0 

7.8 
13.8 

9.8 
17.5 
12.4 

22.1 
15.7 


300 

1.8 

1.3 
2.9 
2.0 

4.6 

3.3 

7.3 

5.2 

9.2 

6.6 

11.7 

8.3 

14.7 
10.5 


40Q 

1.4 
1.0 
2.2 

1.5 

3.5 

2.5 

5.5 

3.9 

6.9 

4.9 
8.8 
6.2 

11.0 

7.8 


500 

600  1 

700 

800 

900 

1.1 

0.9  ! 

0.8 

0.7 

i 

0.6 

0.8 

0.7  ; 

0.6 

0.5 

0.4 

1.7 

1.4 

1.2 

1.1 

1.0 

1.2 

1.0 

0.9 

0.8 

0.7 

2.8 

2.3 

2.0 

1.7 

1.5 

2.0 

1.6 

1.4 

1.2 

1.1 

4.4 

3.7 

3.1 

2.8 

2.4 

3.1 

2.6 

2.2 

1.9 

1.7 

5.5 

4.6 

4.0 

3.5 

3.1 

3.9 

3.3 

2.8 

2.5 

2.2 

7.6 

5.8 

5.0 

4.4 

3.9 

5.0 

4.1 

3.5 

3.1 

2.8 

8.8 

7.4 

6.3 

5.5 

4.9 

6.3 

5.2 

4.5 

3.9 

3.5 

' _ . - 

..  

1000  I 

0.5 

0.4 

0.9 

0.6 

1.4 
1.0 
2.2 
1.6 
2.8 
2.0 

3.5 

2.5 
4.4 
3.1 


PRACTICAL  ECONOMIES  IN  DISTRIBUTION 


1165 


anyone  studying  this  subject  should  prepare 
and  also  to  give  a basis  for  the  sample  calcu- 
lations made  later. 

Table  VII  shows  approximate  costs  of 
erected  poles  when  erected  singly  or  in  lots 
up  to  ten  in  the  same  vicinity.  It  is  very 
evident  that,  particularly  in  the  smaller  sizes 
which  are  used  largely  in  local  distribution, 


it  is  very  advantageous  to  erect  a large 
number  at  one  time.  In  fact  if,  in  a given 
section,  the  load  gradually  grew  so  as  to  call 
for  two  40-ft.  poles  at  a time,  erected  through- 
out the  year,  till  seven  were  standing,  it 
would  have  been  just  as  cheap  to  have  erected 
ten  in  the  first  place.  This  means  that  ten 
poles  could  be  erected  ready  for  new  business 


Table  III  ’ 


KILOWATT  CAPACITY  OF  SECONDARY  MAINS 
Uniformly  Distributed  Load,  Transformer  at  One  End 
Single-Phase;  1 Per  Cent  Maximum  Volts  Loss;  224  Volts  Delivered 


Wire 

UPPER  FIGURES  KILOWATT  CAPACITY — 95  PER 
LOWER  FIGURES  KILOWATT  CAPACITY 80  PER 

CENT  P-F. 
CENT  P-F. 

(lights) 

(motors) 

Size 
B &S 

Distance  in  Feet 

p 

Maximum 

100 

200  300 

400 

oOO 

600 

700 

800 

900 

1000 

6 j 

0.95 

14.9 

10.4 

5.2  1 3.4 

. 2.6 

2.0 

1.7 

1.6 

1.3V 

1.2 

1.0 

^ 1 

1.00 

12.5 

7.8 

3.9  1 2.6 

1.9 

1.6 

1.3 

1.2 

1.0 

0.8 

0.8 

4 1 

0.90 

19.1 

15.6 

7.8  ; 5.2 

3.9 

3.2 

2.6 

2.2 

2.0 

1.8 

1.6 

1 

0.91 

16.1 

11.2 

5.6  ' 3.8 

2.7 

2.2 

1.9 

1.6 

1.4 

1.2 

1.1 

2 / 

0.85 

26.6 

23.6 

11.8  1 7.8 

5.9 

4.8 

3.9 

3.4- 

2.9 

2.6 

2.4 

0.79 

22.4 

15.6 

7.8  ' 5.2 

3.9 

3.2 

2.6 

2.2 

1.9 

1.8 

1.6 

0 ( 

0.76 

42.6 

33.6 

16.8  i 11.2 

8.5. 

6.8 

5.6 

4.8 

4.2 

3.8 

3.4 

^ 1 

0.67 

35.9 

21.0 

10.5  ; 7.0 

5.2 

4.2 

3.5 

3.0 

2.6 

2.4 

2.1 

00  j 

0.74 

48.0 

41.0 

20.5  13.6 

10.3 

8.2 

6.8 

5.1 

4.6 

4.1 

> 

0.60 

40.3 

23.6 

11.8  j 7.8 

5.9 

4.8 

3.9 

3.4 

2.9 

2.6 

2.4 

000  ] 

0.67 

58.6 

46.8 

23.4  I 15.6 

11.7 

9.4 

7.8 

6.8 

5.9 

5.2 

4.7 

0.51 

49.3 

25.4 

12.7  1 8.4 

6.3 

5.0 

4.2 

3.6 

3.2 

2.8 

2.5 

0000  I 

0.62 

69.2 

54.8 

27.4  18.2 

13.7 

11.0 

9.1 

7.8 

6.9 

6.0 

5.5 

0.48 

59.3 

30.0 

15.0  1 10.0 

7.5 

6.0 

5.0 

4.2 

3.8 

3.4 

3.0 

Table  IV 

KILOWATT  CAPACITY  OF  SECONDARY  MAINS 
Uniformly  Distributed  Load,  Tr,ansformer  at  One  End 
Single-Phase;  1 Per  Cent  Power  Loss;  224  Volts  Delivered 


Wire 


UPPER  FIGURES  KILOWATT  CAPACITY 95  PER  CENT  P-F.  (LIGHTS) 

LOWER  FIGURES  KILOWATT  CAPACITY 80  PER  CENT  P-F.  (MOTORS) 


Size 

B.&S. 

p 

Maximum 

Distance  in  Feet 

— 

100 

200 

300 

400 

500 

600 

700 

800 

900 

1000 

6 { 

1.00 

14.9 

14.9  * 

8.2 

5.4 

4.0 

3.3 

2.7 

2.4 

2.1 

1.8 

1.6 

1.00 

12.5 

12.1 

5.8 

3.9 

2.8 

2.4 

1.9 

1.8 

1.5 

1.2 

1.2 

4 { 

1.00 

ib.l 

19.1  * 

13.1 

8.7 

6.4 

5.2 

4.3 

3.7 

3.3 

2.8 

2.6 

1.00 

16.1  1 

16.1  * 

9.1 

6.0 

4.6 

3.6 

3.0 

2.7 

2.2 

2.1 

1.8 

2 j 

1.00 

26.6  1 

26.6  * 

20.8 

13.8 

10.3 

8.3 

6.9 

6.0 

5.2 

4.5 

4.2 

1 

0 i 

1.00 

22.4 

22.4  * 

14.8 

9.9 

7.3 

6.0 

4.9 

4.2 

3.7 

3.3 

3.0 

1.00 

42.6 

42.6  * 

33.0 

22.2 

16.0 

13.4 

11.1 

9.6 

8.2 

7.5 

6.6 

1 

00  1 
000  / 

1.00 

35.9 

35.9  * 

23.6 

15.6 

11.7 

9.3 

7.8 

6.6 

5.8 

5.1 

4.6 

1.00 

48.0 

48.0  * 

40.8 

27.6 

20.7 

16.5 

13.8 

12.0 

10.3 

9.3 

8.2 

1.00 

40.3 

40.3  * 

29.5 

19.8 

14.7 

11.7 

9.9 

8.4 

7.3 

6.6 

5.8 

1.00 

58.6 

58.6  * 

52.5 

35.0 

26.3 

21.0 

17.5 

15.0 

13.2 

11.7 

10.5 

) 

1.00 

49  .d 

49.3  * 

37.2 

24.9' 

18.6 

15.0 

12.4 

10.5 

9.3 

8.4 

7.5 

0000  1 

1.00 

69.2 

69.2  * 

66.5 

44.0 

33.2 

26.4 

22.0 

18.9 

16.7 

14.7 

13.2 

1:00 

59.3 

59.3  * 

48.0 

31.5 

23.6 

18.9 

, 15.8 

13.5 

11.7 

10.5 

9.4 

* Maximum  allowable  load;  less  than  1 per  cent  power  loss. 


1166 


GENERAL  ELECTRIC  REVIEW 


with  a chance  that  three  might  never  be  used 
and  still  it  would  cost  no  more  than  the 
other  “piece  meal’’  method. 

Similar  and  indeed  more  striking  lessons 
could  be  drawn  from  Table  VIII,  showing 
the  cost  of  erected  secondary  wires.  For 
instance,  if  the  initial  financial  burden  were 
not  too  great,  and  if  streets  were  open  so 


that  it  would  be  possible  to  erect  secondaries 
in  a residential  section  in  runs  of  1000  ft. 
at  a time  instead  of  200  ft.  at  a time.  No.  2 
wire  could  be  used  instead  of  No.  6 without 
additional  cost.  This  would  mean  a tremen- 
dous difference  in  the  capacity  of  the  system 
as  can  be  seen  by  referring  to  these  two  sizes 
in  Table  VI  for  1000  ft.,  which  shows  that 


Table  V 

KILOWATT  CAPACITY  OF  SECONDARY  MAINS 
Uniformly  Distributed  Load,  Transformer  in  Center 
Single-Phase;  1 Per  Cent  Maximum  Volts  Loss;  224  Volts  Delivered 


Wire 


UPPER  FIGURES  KILOWATT  CAPACITY — 95  PER  CENT  P-F.  (LIGHTS) 
LOWER  FIGURES  KILOWATT  CAPACITY — 80  PER  CENT  P-F.  (MOTORS) 


Size 

B.&S. 

Maximum 

Distance 

in  Feet 

100  * 

200 

300 

400 

500 

600 

700 

800 

900 

1000 

0.95 

29.8 

29.8 

>3-2 

20.8 

13.9 

6.. 

10.4 

8.0 

' ■/ 
6.9 

5.9 

5.2 

4.6 

vb 

4.2 

® 1 

1.00 

25.0 

25.0 

15.6 

10.4 

7.8 

6.2 

5.2 

4.5 

3.9 

3.5 

3.1 

4^ 

0.90 

38.2 

38.2 

31.2 

20.8 

15.6 

12.5 

10.4 

8.9 

7.8 

6.9 

6.2 

^ 1 

0.91 

32.2 

32.2 

22.4 

14.9 

11.4 

8.9 

7.5 

6.4 

5.6 

5.0 

4.5 

0.85 

53.2 

53.2 

47.2 

31.4 

23.6 

18.9 

15.7 

13.5 

11.8 

10.5 

9.4 

0.79 

44.8 

44.8 

31.2 

20.8 

15.6 

12.5 

10.4 

8.9 

7.8 

6.9 

6.2 

0.76 

85.2 

85.2 

67.2 

44.8 

33.6 

26.8 

22.4 

19.2 

16.8 

14.9 

13.4 

0.67 

71.8 

71.8 

42.0 

28.0 

21.0 

16.8 

14.0 

12.0 

10.5 

9.3 

8.4 

00  1 

0.74 

96.0 

96.0 

82.0 

54.6 

41.0 

32.8 

27.3 

23.4 

20.5 

18.2 

16.4 

0.60 

80.6 

80.6 

47.2 

31.5 

23.6 

18.9 

15.8 

13.5 

11.8 

10.5 

9.4 

000  1 

0.67 

117.2 

117.2 

93.6 

62.4 

46.8 

87.4 

31.2 

26.8 

23.4 

20.8 

18.7 

0.51 

98.6 

98.6 

50.8 

33.9 

25.4 

20.3 

17.0 

14.5 

12.7 

11.3 

10.2 

0000  1 

0.62 

138.4 

138.4 

109.6 

73.0 

54.8 

43.9 

36.5 

31.3 

27.4 

24.4 

21.9 

0.48 

118.6 

118.6 

60.0 

40.0 

30.0 

24.0 

20.0 

17.1 

15.0 

13.3 

12.0 

* Maximum  allowable  load;  less  than  1 per  cent  volts  loss. 


Table  VI 

KILOWATT  CAPACITY  OF  SECONDARY  MAINS 
Uniformly  Distributed  Load,  Transformer  in  Center 
Single-Phase;  1 Per  Cent  Power  Loss;  224  Volts  Delivered 


UPPER  FIGURES  KILOWATT  CAPACITY — 95  PER  CENT  P-F.  (LIGHTS) 
LOWER  FIGURES  KILOWATT  CAPACITY — 80  PER  CENT  P-F.  (MOTOR) 


Size 

B.&S. 

Maximum 

Distance  in  Feet 

p 

100  * 

200 

300 

400 

500 

600 

700 

800 

900 

1000 

1.00 

29.8 

29.8 

29.8  * 

21.8 

16.5 

13.1 

11.0 

9.3 

8.2 

7.3 

6.6 

1.00 

25.0 

25.0 

23.2 

16.8 

11.7 

9.3 

7.8 

6.7 

5.8 

5.2 

4.6 

1.00 

38.2 

38.2 

38.2  * 

34.8 

26.1 

20.8 

17.4 

14.9 

. 3.1 

11.5 

10.5 

1.00 

32.2 

32.2 

32.2  * 

24.5 

18.3 

14.6 

12.2 

10.4 

9.1 

8.1 

7.3 

9 / 

1.00 

53.2 

53.2 

53.2  * 

53.2  * 

41.5 

33.1 

28.6 

23.7 

20.8 

18.5 

16.6 

1.00 

44.8 

44.8 

44.8  * 

39.3 

29.9 

23.7 

19.8 

16.9 

14.9 

13.4 

11.8 

n / 

1.00 

85.2 

85.2 

85.2  * 

85.2  * 

66.0 

53.0 

44.0 

37.6 

33.0 

29.4 

26.4 

1.00 

71.8 

71.8 

71.8  * 

63.0 

47.0 

37.7 

31.4 

26.9 

23.6 

21.0 

■ 18.9 

1.00 

96.0 

96.0 

96.0  * 

96.0  * 

83.0 

63.2 

55.2 

47.3 

41.5 

36.8 

33.2 

00  1 

1.00 

80.8 

80.6 

80.6  * 

78.5 

59.1 

47.2 

39.4 

33.9 

29.6 

26.2 

23.6 

( 

1.00 

117.2 

117.2 

117.2  * 

117.2  * 

104.6 

83.9 

70.0 

59.9 

52.5 

46.6 

42.0 

000  { 

1.00 

98.6 

98.6 

98.6  * 

98.6  * 

74.2 

59.4 

49.5 

42.5 

37.2 

33.0 

29.9 

0000  1 

1.00 

138.4 

138.4 

138.4  * 

138.4  * 

132.0 

106.0 

88.3 

75.9 

66.4 

58.9 

53.0 

1.00 

118.6 

118.6 

118.6  * 

118.6  * 

94.0 

75.5 

62.7 

54.0 

47.0 

41.9 

37.8 

* Maximum  allowable  load;  less  than  1 per  cent  power  loss. 


PRACTICAL  ECONOMIES  IN  DISTRIBUTION 


1167 


Table  VII 

COST  IN  DOLLARS  OF  ONE  ERECTED  WOOD  POLE 


Length  of  | number  of  poles  erected  at  one  time 


Pole 
in  Feet 

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

35 

$16.00 

$14.00 

$12.00 

$11.00 

$10.50 

$10.00 

$9.60 

$9.40 

$9.20 

$9.00 

40 

18.25 

16.25 

14.25 

13.25 

12.75 

12.25 

11.85 

11.65 

11.45 

11.25 

45 

20.50 

18.50 

16.50 

15.50 

15.00 

14.50 

14.10 

13.90 

13.70 

13.50 

50 

23.25 

21.25 

19.25 

18.25 

17.75 

17.25 

16.85 

16.65 

16.45 

16  25 

55 

27.25 

25.25 

23.25 

22.00 

21.25 

20.75 

20.10 

19.75 

19.45 

19.25 

60 

35.50 

33.50 

31.50 

30.25 

29.75 

29.00 

28.35 

28.00 

27.70 

27.50 

65 

37.50 

35.50 

33.50 

32.25 

31.75 

31.00 

30.35 

30.00 

29.70 

29.50 

70 

39.50 

37.50 

35.50 

34.25 

33.75 

33.00 

32.35 

32.00 

31.70 

31.50 

Table  VIII 

COST  IN  DOLLARS  PER  100  FEET  FOR  THREE  ERECTED  SECONDARY  WIRES  ON  POLES 
ALREADY  ERECTED  BUT  NOT  ARMED  OR  GUYED.  1 SPAN  = 100  FEET 


Wire 

Size 

B.&S. 

DISTANCE 

100 

200 

300 

400 

500 

600 

700 

800 

900 

1000 

6 

$8.50 

$6.90 

$6.10 

$5.55 

$5.15 

$4.85 

$4.60 

$4,45 

$4.30 

$4.15 

4 

9.55 

7.95 

7.15 

6.60 

6.20 

5.95 

5.70 

5.55 

5.40 

5,25 

2 

11.20 

9.60 

8.80 

8.25 

7.85 

7.60 

7.35 

7.20 

7.10 

6.95 

0 

13.65 

12.05 

11.25 

10.70 

10.35 

10.10 

9.85 

9.70 

9.60 

9.45 

00 

15.30 

13.60 

12.95 

12.40 

12.05 

11.80 

11.55 

11.40 

11.30 

11  15 

000 

17.70 

16.10 

15.35 

14.80 

14.45 

14.10 

13.90 

13.70 

13.55 

13  35 

0000 

19.30 

17.70 

16.95 

16.40 

16.05 

15.75 

15.40 

15.15 

14.95 

14.75 

j Table  IX 

1 CREDIT  IN  DOLLARS  PER  100  FEET  FOR  WIRE  REMOVED  WHEN  SAME  IS  REPLACED 
BY  OTHER  WIRE  AND  REMOVED  WIRE  HAS  NOT  PASSED  USEFUL  LIFE 


Wire 

Size 

B.&S. 

LENGTH  IN  FEET  OF  RE.MOVED 

WIRE 

100 

200 

300 

400 

500 

600 

'700 

800 

900 

1000 

6 

i $0.35 

$0.35 

$0.35 

$0.45 

$0.55 

$0.70  1 

$0.80  ! 

$0.90 

$0.90 

$0.90 

4 

1 .55 

.55 

.55 

.75 

.80 

1.05 

1.15  I 

1.35 

1.35  i 

1.35 

2 

1.05 

1.05 

1.05 

1.20 

1.50 

1.75 

2.00 

2.20  1 

2.20 

2.20 

0 

1.75 

1.  /5 

1.75 

2.10 

2.45 

2.85  1 

3.20  1 

3.55  1 

3.55 

3.55 

00 

2.20 

2.20 

2.20 

2.60 

3.05 

3.50  ' 

3.95 

4.40  1 

4.40 

4 40 

000 

2.85 

2.85 

2.85 

3.40 

3.95 

4.50  1 

5.15  i 

5.70 

5.70 

5 70 

0000 

8. bo 

3.50 

3.50 

4.20 

4.90 

5.60  ; 

6.35 

7.05  : 

7.05  ' 

7.05 

Table  X 

COST  IN  DOLLARS  OF  ERECTION  OF  A TRANSFORMER  ON  AN  ERECTED  POLE  WITH 
PRIMARY  AND  SECONDARY  LINES  ALREADY  ON  POLE;  ALSO  COST  OF 
CHANGING  TO  ANOTHER  SIZE 


Group 

Transformer 

Size 

Kv-a. 

Original 

Installation 

Changing 

to 

Group  A 

Changing 

to 

Group  B 

Changing 

to 

Group  C 

A 

B 

C 

1 to  10 
15  to  25 
30  to  50 

$5.50 

6.50 

7.00 

$4.00 

3.50 

5.00 

$5.00 

5.00 

5.00 

$6.00 

6.00 

6.00 

\ 


1168 


GENERAL  ELECTRIC  REVIEW 


through  the  1000  ft.  with  the  transformer 
in  the  center  the  No.  6 wire  would  carry 

6.6  kw.  while  the  No.  2 wire  would  carry 

16.6  kw.  This  is  an  increase  to  2^  times  the 
capacity  without  additional  expense  if  one 
can  just  look  ahead  far  enough. 

On  account  of  the  increase  in  load  in  any 
section  it  may  be  necessary  at  any  time  to 
replace  small  wire  with  a conductor  of  larger 
size.  It  is  therefore  interesting  in  this  con- 
nection to  determine  how  much  return  can 
be  had  for  removing  the  wire  which  is  so 
expensive  to  erect.  This  return  is  here  termed 
“credit”  and  is  the  scrap  value  of  the  wire 
minus  the  cost  of  removing  it.  These  credits 
are  shown  in  Table  IX  for  wire  which  may 
still  be  used  over  again.  The  credits  mn 
higher  for  the  greater  lengths  because  they 
might  be  returned  to  second-hand  stock  while 
the  shorter  lengths  would  just  be  cut  down 
and  scrapped.  A comparison  of  this  table  with 
Table  VIII  shows  strikingly  the  results  ot  not 
building  lines  large  enough  at  first  to  carry 
all  load  which  may  arise  during  the  useful  lite 

of  the  wire.  . , 

Now  that  the  poles  and  primary  and 
secondary  lines  of  a distribution  system  have 
been  considered,  it  is  time  to  consider  the 
transformer  which  ties  together  the  pnmary 
and  the  secondary  mains.  This  has  properties 
similar  to  those  of  poles  and  wires  m that  it 
costs  money  as  is  clearly  shown  m Table  XL 
It  also  shares  with  the  wires  m absorlung 
some  of  the  energy  which  it  transmits.  But 
it  goes  further  than  that,  absorbing  enerp’ 
whether  it  is  transmitting  any  or  not.  this 
constant  drain  of  energy  is  c^led  the  core 
loss,  and  is  shown  in  Table  XI  for  trans- 
formers from  1 to  50  kv-a.,  both  m watts  and 
in  cost  in  dollars  per  annum  at  cent  per 

^'Vhere  has  been  some  discussion  about  the 
rate  at  which  the  core  loss  should  be  charged. 
Some  would  say  that  it  must  take  share 
of  the  generating  substation  and  distribution 
costs  while  some  would  merely  charge  its 
coal  ’cost.  This  latter  would  appear  to  be 
more  nearly  correct  since  the  core  loss  totals 
less  than  1 per  cent  of  the  peak  load  and 
therefore  has  a negligible  effect  on  the 
generating  capacity.  Its  effect  on  the  remain- 
der of  the  system  is  so  distributed  over  the 
whole  that  its  effect  is  absolutely  negligible^ 
fudging  it  by  the  standards  for  commercial 
loads,  it  has  a 100  per  cent  load  factor  on  the 
24-hr  basis  and  is  so  distributed  that  it  r 
nuires  no  additional  apparatus  and  it  is  there- 
fore entitled  to  the  absolute  minimum  rate. 


Table  XI  also  shows  the  cost  of  the  various 
sizes  of  transformers  and  the  cost  of  erection. 
From  these  figures  with  interest  at  6 per  cent 
and  depreciation  10  per  cent,  on  the  basis 
of  a life  of  10  years,  the  cost  of  keeping  a 
transformer  on  the  line  for  a year  has  been 
worked  out  and  is  shown.  Some  would  like 
to  claim  longer  life  than  10  years,  thoug 
general  experience  would  not  seem  to  warrant 
it  for  the  average  size  pole  type  transfomen 
Of  course,  these  figures  should  be  modified 
by  the  latest  data  on  each  system  m making 

the  caleulations.  . , 

The  core  loss  has  been  materially  reduced 
in  recent  years.  It  probably  makes  rnore 
expensive  construction  to  reduce  the  loss, 
and  by  letting  it  run  higher  the  transformer 
should  be  cheaper.  It  is  therefore  the  business 
of  the  manufacturing  companies  to  obtain 
a true  balance  between  these  factors. 

No  allowance  has  been  made  for  mmn- 
tenance  charges  against  the  transformer  since 
many  companies  have  done  practically  no 
maintenance  work  on  them  and  no  definite 
figures  as  to  the  amount  necessary  or  how 
it  will  improve  the  life  of  the  transformer  or 
its  capacity,  are  readily  available  Howeve^ 
just  a superficial  study  of  the  table  will  show 
that  if  10  years  is  the  true  life  of  a oO-kv-a.  ^ 
transformer,  without  any  maintenance^  wor  , 
work  that  would  improve  the  life  to  lo  years  ,, 
could  cost  as  much  as  $10.00  per  year.  This  ( 
is  easily  enough  to  pay  for  most  complete  ! 
lightning  protection,  purification  ot  ttie  on, 
and  complete  cleaning  when  out  of  service 
and  still  leave  a very  wide  margin  of  protit. 

Many  people  familiar  with  transformers 
can  scarcely  tell  the  difference  between  a 
40  and  a 50-kv-a.  transformer  when  they  see| 
it  on  the  pole.  Yet  the  last  column  shows  the  < 
difference  is  $8.10  a year.  A practical  man  m 
choosing  whether  to  put  up  a 40  or  a ^u-, 
kv-a.  transformer  will  very  likely  decide  to 
use  the  50,  saying:  “It  will  be  needed  in  a 

couple  of  years  anyway.  _ However  it  will 
cost  $16.20  more  in  that  time  and  it  wou 
cost  only  $6.00  (Table  X)  to  change  |t.  This 
last  column  (Table  XI)  shows  that  if  tl^ 
average  size  of  transfonners  on  any  system 
could  be  reduced  say  from  15  kv-a.  to  10 
kv-a  it  would  warrant  the  expenditure  o 
approximately  $6.00  per  transformer^ 
annum.  This  is  easily  enough  to  pay  ve^ 
complete  tests  and  records  of  ever\  trans- 

In  this  connection  it  is  not  out  of  place  tc 
consider  briefly  what  tests  and  records  axi 
necessary.  On  small  systems  with  one  or  twc 


PRACTICAL  ECONOMIES  IN  DISTRIBUTION 


1169 


men  handling  all  records  it  is  very  generally 
possible  to  have  one  set  of  records  for  all. 
But  on  larger  systems  it  becomes  necessary 
to  have  records  of  customers’  loads  in  the 
contract  department,  meter  department,  and 
distribution  department.  Experience  has 
shown  the  great  difficulty  of  keeping  these 
records  up  to  date,  particularly  with  medium 
size  business  places,  where  different  sizes  of 
lamps  are  kept  on  hand  and  used  on  different- 
evenings  according  to  the  season  of  year  and 
business  expected.  So  it  is  an  open  question 
in  the  distribution  department,  with  which 


2 cents  per  kw-hr.  since  it  is  a peak  load.  This 
is  discussed  more  fully  in  considering  rate  for 
energy  losses  in  the  secondary  (page  1172). 

The  transformer  has  been  treated  in  a 
manner  slightly  different  from  that  in  which 
the  pole  and  wire  costs  were  treated;  that  is, 
its  cost  per  annum  has  been  determined  as 
well  as  the  initial  cost.  It  is  now  proposed 
to  do  the  same  for  secondary  wires  but,  since 
the  previous  tables  show  plainly  that  it  is 
uneconomical  to  erect  wires  in  short  sections, 
figures  for  1000-ft.  sections  only  have  been 
made  up.  These  are  shown  in  Table  XIII. 


Table  XI 

INITIAL  COST  OF,  AND  ANNUAL  CHARGES  AGAINST  POLE  TYPE  TRANSFORMERS 


Life,  10  Years;  Depreciation,  10  Per  Cent;  Interest,  6 Per  Cent;  Total  Capital  Charges,  16  Per  Cent; 
Energy  to  Supply  Core  Loss,  Cent  per  Kw-Hr. 


Kv-a. 

COST  IN  DOLLARS 

CORE 

LOSS 

Total 

Annual 

Charges 

Original 

Erection 

Total 

Annual 

Watts 

Cost 
per  Year 

1.0 

$20.00 

$5.50 

$25.50 

$4.10 

25 

$1.10' 

$5.20 

2.0 

30.00 

5.50 

35.50 

5.70 

'35 

1.50 

7.20 

3.0 

40.00 

5.50 

45.50 

7.30 

45 

1.95 

9.25 

4.0 

50.00 

5.50 

55.50 

8.90 

50 

2.20 

11.10 

5.0 

55.00 

5.50 

60.50 

9.70 

55 

2.40 

12.10 

7.5 

75.00 

5.50 

?0.50 

11.30 

75 

3.30 

14.60 

10.0 

90.00 

5.50 

95.50 

15.30- 

90 

3.90 

19.20 

15.0 

120.00 

6.50 

126.50 

20.20 

120 

5.25 

25.45 

20.0 

150.00 

6.50 

156.50 

25.00  - 

145 

6.35 

31.35 

25.0 

180.00 

6.50 

186.50 

29.80 

170 

7.45 

37.25 

30.0 

200.00 

7.00 

207.00 

33.00  -- 

190 

8.30 

41.30 

40.0 

240.00 

7.00 

247.00 

39.50 

225 

9.80 

49.30 

50.0 

■ 280.00 

7.00 

287.00 

46.00 

260 

11.40 

57.40 

only  we  are  now  concerned,  whether  it  is 
necessary  to  keep  any  record  of  load  except 
for  the  larger  customers — that  is,  for  the 
customers  whose  loads  are  say  one-fourth  or 
one-half  of  the  transformer  capacity  supplying 
themr  But  it  is  evident  from  Table  XI  that 
it  is  most  necessary  to  keep  records  of  actual 
tests,  showing  that  the  transformers  are 
working  at  least  up  to  their  rating,  and,  if  they 
will  stand  it,  above  their  ratings  during  the 
peak.  The  two  factors  that  determine  whether 
they  will  stand  it  or  not  are  the  temperature 
and  the  regulation.  This  is  a great  subject 
in  itself  and  there  is  not  space  here  to  say 
more  than  that  one  central  station  has  just 
started  some  practical  in-service  tests  on  this 
basis  and  there  may  be  some  very  interesting 
results  to  report  in  the  future. 

As  a matter  of  interest  and  for  subsequent 
use,  the  copper  loss  and  regulation  of  trans- 
formers are  shown:  in  Table  XII.  The  cost 
cl  energy  for  copper  loss  has  been  assumed  at 


PRACTICAL  COMBINATION  OF  DATA 
FOR  ECOMONICAL  RESULTS 

In  the  preceding  sections  of  this  article 
the  losses  in  various  apparatus  and  the  cost 
of  maintaining  it  in  service  have  been  shown. 
It  is  now  proposed  to  combine  these  to  show 
what  is  the  truly  economical  design  for  a 
secondary  distribution  system. 

This  would  appear  a very  complicated 
problem,  and  indeed  it  is.  But  it  is  here  that 
the  “practical  man’’  comes  in  to  simplify 
matters.  For  instance,  in  considering  the 
question  of  service  to  a row  of  houses  by  wires 
run  along  the  rear  on  brackets  from  one  end, 
the  “practical  man’’  says  it  is  useless  to 
consider  running  the  primary  lines  in  to  a 
transformer  placed  in  the  center  of  the  row, 
no  matter  how  cheap  a job  it  will  make,  on 
account  of  the  same  objections  which  have 
been  advanced  against  the  “radial  system,’’ 
and  also  on  account  of  the  life  hazard  of 


{ 


1170 


GENERAL  ELECTRIC  REVIEW 


Table  XII 

TRANSFORMER  REGULATION  AND  COPPER  LOSS  AND  COST  PER  YEAR  AT  2 CENTS 
PER  KW-HR.  FOR  FULL  LOAD  OPERATION  1 HOUR  PER  DAY 


Size 

Kv-a. 

Regulation 
95  Per  Cent 
P-F. 

COPPER  LOSS 

Size 

Kv-a. 

Regulation 
95  Per  Cent 
P-F. 

COPPER  LOSS 

Watts 

Cost 

Watts 

Cost 

1.0 

2.5 

30 

S0.22 

15.0 

1.5 

220 

.11.60 

2.0 

2.5 

50 

.36 

20.0 

1.4 

295 

2.16 

3.0 

2.3 

70 

.51 

25.0 

1.4 

355 

2.59 

4.0 

2.1 

85 

.62 

30.0 

1.4 

430 

3.14 

5.0 

1.9 

95 

.69 

40.0 

1.3 

485 

3.54 

7.5 

1.7 

120 

.88 

50.0 

1.2 

600 

4.38 

10.0 

1.6 

160 

1.17 

Table  XIII 

DATA  ON  ANNUAL  CHARGES  AGAINST  1000  FEET  OF  THREE-WIRE  SECONDARY, 

EXCLUSIVE  OF  COST  OF  POLES 


"Wire 

Size 

B.&S. 

Initial 
Cost  from 
Table  VIII 

Average 

Life 

Years 

Depreciation 

Interest 

Total  Capital  Charges 

Maintenance 

Total 

Annual 

Charges 

Per  Cent 

Per  Cent 

Per  Cent 

6 

S41.50 

25 

4.0 

6.0 

10.0  ‘ 

■S4.10 

$3.00 

$7.10 

4 

52.50 

25 

4.0 

6.0 

10.0 

5.20 

3.00 

8.20 

2 

69.50 

25 

4.0 

6.0 

10.0 

7.00 

3.00 

10.00 

0 

94.50 

30 

3.3 

6.0 

9.3 

8.80 

3.00 

11.80 

00 

111.50 

30 

3.3 

6.0 

9.3 

10.40 

3.00 

13.40 

000 

133.50 

35 

3.0 

6.0 

9.0 

12.00 

3.00 

15.00 

0000 

147.50 

40 

2.5 

6.0 

8.5 

12.50 

3.00 

15.50 

Table  XIV 


ANNUAL  CHARGES  AGAINST  A THREE-WIRE  SECONDARY  SYSTEM,  1000  FEET  LONG, 
SUPPLIED  BY  A 30-KILOWATT  TRANSFORMER  IN  THE  CENTER,  WITH  A , .* 
UNIFORMLY  DISTRIBUTED  LOAD  OF  30  KILOWATTS,  OF  95  PER  CENT  * 

POWER-FACTOR 

224  Volts  Delivered;  Rate,  2 Cents  per  Kw-Hr. ; Showing  Most  Economical  Size  of  Wire 


1 


II 


Wire 

Size 

B.&S. 

POWER  LOSS 

ANNUAL  FIXED 
CHARGES 

TOTAL  FIXED  AND  OPERATING  ANNUAL 
CHARGES  FOR  DIFFERENT  DAILY 
PERIODS  OF  OPERATION 

Max. 

Volts 

Loss 

Per 

Cent 

Secon 

(From 

Table 

VII) 

Per  Cent 

dary 

In 

Kw. 

Trans- 
former 
Copper 
in  Kw. 

Total 

Kw. 

Annual 
Cost 
with 
Load  on 
1 Hour 
per  Day 

Trans  - 
former 

Lines 

Total 

1 

Hour 

2 

Hours 

3 

Hours 

5 

Hours 

8 

Hours 

10 

Hours 

6 

4.5 

1.34 

0.43 

1.77 

$12.90 

$41.30 

$ 7.10 

$48.40 

$61.30 

$74.20 

$87.10 

$112.90 

$151.60 

$177.40 

7.1 

4 

2.8 

0.84 

0.43 

1.27 

9.30 

41.30 

8.20 

49.50 

58.80 

68.10 

77.40 

96.00 

123.90 

142.50 

4.6 

2 

1.8 

0.43 

0.43 

0.96 

7.00 

41.30 

10.00 

51.30 

58.30 

65.30 

72.30 

86.30 

107.30 

121.30 

3.2 

0 

1.13 

C).34 

0.-13 

0.77 

5.60 

4.130 

11.80 

53.10 

58.70 

64.30 

69.90 

81.10 

97.90 

109.10 

2.2 

00 

0.90 

0.27 

0.43 

0.70 

5.10 

41.30 

13.40 

54.70 

59.80 

64.90 

70.00 

80.20 

95.50 

105.70 

1.8 

000 

0.71 

0.21 

0.43 

0.64 

4.70 

41.30 

15.00 

56.30 

61.00 

65.70 

70.40 

79.80 

93.90 

103.30 

1.6 

0000 

0.56 

0.17 

0.43 

0.60 

4.40 

41.30 

15.50 

56.80 

61.20 

65.60 

70.00 

78.80 

92.00 

101.20 

1.4 

\ 

PRACTICAL  ECONOMIES  IN  DISTRIBUTION 


1171 


running,  primary  wires  open  on  a row  of 
residences.  This  is,  of  course,  an  extreme 
case,  but  it  is  brother  to  the  case  of  a moderate 
size  load  on  a side  street ; that  is,  a street  that 
has  not  been  chosen  for  a primary  branch, 
as  in  Fig.  2.  The  practical  man  says:  “Let  it 
cost  more,  but  if  any  reasonable  arrangement 
can  be  made,  keep  the  transformers  on  the 
main  street.”  Further,  the  junction  pole  at  a 
comer  would  appear  to  be  the  ideal  place 
to  feed  economically  in  both  directions ; but 
objection  is  rightly  made  that  a junction 
pole  is  complicated  enough  without  the  trans- 
formers; it  is  already  the  most  difficult  to 
maintain  and  renew,  and  it  usually  of  necessity 
has  a street  lamp.  This  limits  the  transformer 
poles  to  those  in  the  center  of  the  block. 
There  may  also  be  some  alleys  requiring 
lines  and  therefore  junction  poles,  so  in  a 
block  500  ft.  long  there  may  be  only  two  or 
three  poles  available  for  transformers.  Con- 
sidering that  there  may  be  separate  light  and 
power  transformers  required,  apparently  only 
one  pole  per  block  will  be  available  for  a light- 
ing transformer,  unless  sufficient  economy  by 
using  more  can  be  shown  to  warrant  the 
shortening  of  the  spans  and  the  erection  of  an 
additional  pole.  Then,  the  practical  man 
goes  further — he  says:  “Transformers,  like  all 
other  apparatus  on  a line,  are  points  of 
trouble,”  and  he  wants  as  few  of  them  as 
•possible,  in  order  to  maintain  continuous 
service,  so  that  one  transformer  for  every 
two  blocks  would  be  much  better.  Conclud- 
ing, he  thinks  that  a secondary  system,  such  as 
shown  in  Fig.  4,  considering  the  primary 
lines  running  on  the  “main  streets”  would 
be  ideal,  except  that  the  transformers  would 
have  to  be  moved  to  the  pole  next  to  the 
corner. 

So  the  problem  would  on  the  whole  appear 
to  be  much  simplified  by  the  apparent 
complications  of  practical  conditions. 

The  most  economical  condition  is,  of  course, 
when  the  sum  of  the  fixed  capital  and  main- 
tenance charges,  and  the  operating  charges 
or  cost  of  the  power  loss  are  a minimum.  The 
; question  of  increased  or  decreased  consump- 
tion of  current  by  the  lamps  might  at  first 
be  thought  to  influence  this  problem,  but  it  has 
ji  no  connection.  If  lamps  are  supplied  rated 
j at  exactly  the  service  voltage  of  each  individ- 
I ual  customer,  it  then  makes  no  difference 
what  is  the  range  in  voltage  from  the  nearest 
to  the  most  distant  service.  If  lamps  are 
supplied  to  all  alike  of  the  average  voltage 
on  the  secondary,  then  the  increase  in 
consumption  of  some  will  offset  the  decrease 


by  others,  so  far  as  the  central  station  is 
concerned.  The  results  of  the  calculations 
in  Table  XIV  amply  justify  this  assumption 
and  preclude  the  necessity  of  further  discuss- 
ing the  ethics  of  the  matter. 


•d 

Cross 

<8 

fUey 

# Tro/ys/orrrer 
— 3y//reS&cor?£/or^ 

St. 

Cross  t 

k 

. St. 

Cross 

St. 

\ 

Crass  A 

. St 

\ 

1 

\ 

•C: 

Fig.  4.  Ideal  Secondary  Distribution 


It  is  not  proposed  here  to  work  out  econom- 
ical conditions  for  all  cases  but  to  give  an 
example  of  the  procedure.  The  case  taken 
will  be  that  which  the  forenamed  practical 
considerations  would  point  to  as  normal. 
Suppose  there  is  an  actual  combined  running 
load  of  30  kw.  in  two  blocks,  each  500  ft.  long, 
making  a total  length  of  secondary  of  1000  ft. 
(This  is  very  near  the  condition  on  the  main 
business  street  of  a small  town  or  an  outlying 
business  street  of  a large  city.)  The  30  kw. 
can  just  be  carried  by  No.  6 wire  without 
over-heating.  The  question  is,  what  size 
wire  shall  be  used  to  supply  the  load.  The 
charges  for  the  30  kv-a.  transformer  will  be 
fixed.  The  charges  for  the  wire  will  be  fixed 
for  each  size  regardless  of  the  length  of  time 
the  load  is  in  use.  The  operating  costs  or 
power  loss  in  the  secondary  will  vary  with 
the  length  of  time  the  load  is  in  use,  and  the 
copper  loss  of  the  transformer  is  included  with 
it,  since  it  varies  in  exactly  the  same  manner. 
It  is  therefore  evident  that  the  answer,  i.e., 
the  size  of  wire,  will  vary  with  the  length 
of  time  the  load  is  in  use.  Since  the  load  does 


I 


1172 


GENERAL  ELECTRIC  REVIEW 


not  come  on  or  go  off  suddenly  or  stay  at  any 
fixed  value,  and  since  it,  as  well  as  the  time 
in  use,  varies  throughout  the  year,  a rnore 
general  answer  can  be  obtained  by  finding 
the  most  economical  sizes  for  each  period 
of  use  from  1 to  10  hours. 

The  charge  per  kw-hr.  for  energy  losses, 
like  the  charge  for  core  loss  of  a transformer, 
is  open  for  discussion.  It  is  in  reality  the 
total  cost  of  supplying  current  to  the  class  of 
customers  supplied  by  the  secondary  line  in 
question,  minus  the  customer  or^  service  line 
and  meter  charges.  The  practical  way  to 
obtain  this,  until  the  whole  subject  of  distri- 
bution has  been  given  muqh  more  detailed 
attention  than  it  has  received  to  the  preset 
time,  is  to  take  the  average  rate  per  kw-hr. 
paid  by  the  customers  on  a secondary  main 
and  subtract  the  average  charges  per  kw-hr. 
delivered  for  service  and  meter  costs,  the 
figure  of  2 cents  per  kw-hr.  has  been  used  m 
Table  XIV,  but  is  obviously  very  low  for 
lighting  customers.  Any  increase  in  this 
value  would  tend  to  increase  the  economical 
size  of  wire. 

Table  XIV  needs  study,  rather  than 
comment.  It  sums  up  all  that  has  gone  before 
and  shows  most  conclusively  that  there  ^s  an 
economical  size  of  wire  to  be  used  for  every 
condition  and  that  this  size  is  not  far  different 
from  what  the  practical  man  is  accustomed 
to  use,  but  is  right  in  the  range  of  commercial 
practice.  In  the  particular  case  in  hand  it  is 
probably  not  out  of  the  way  to  assume  that 
the  load  would  be  “ on  ” two  or  three  hours  per 
day  as  the  average.  The  table  shows  that  for 
this  use  the  best  size  of  secondary  is  No.  U. 
No.  00  is  so  close  to  the  same  econorny  and 
with  better  economy  if  the  load  should  run 
for  four  hours,  that  it  is  a question  indeed  it 

it  should  not  be  used.  . 

But  while  the  fact  that  the  most  economical 
size  of  wire  can  be  exactly  determined  is  ot 
great  interest,  the  final  column  is  of  even 
greater.  It  shows  that  if  central  stations 
could  afford  to  abandon  their  present  distri- 
bution systems  and  build  new  ones  in  accord- 
ance with  these  principles  of  design  the 
question  of  different  lamp  voltages  for  differ- 
ent customers  would  be  settled.  With  the 
most  economical  size  of  wire  the  range  o 
voltage  in  the  hypothetical  case  considered 
is  only  2.2  per  cent  or  1.1  per  cent  from  the 
average.  This  is  such  a small  amount  that 
it  is  negligible,  as  can  be  seen  by  reference  to 
any  of  the  standard  candle-power  curves 
published  by  lamp  manufacturers.  buch 
curves  show  a change  of  only  3.5  per  cent  in 


candle-power  for  a 1 per  cent  change  in 
voltage.  (A  very  complete  discussion  of  this 
subject  is  given  in  the  report  of  the  Lamp 
Committee  to  the  Pennsylvania  Electrie 

Association,  1913.)  . 

In  other  words,  the  central  station  with 
lines  designed  without  regard  for  initial  cost 
and  with  regard  for  total  economical  opera- 
tion will  supply  service  of  which  there  can  be 
absolutely  no  complaint. 

This  does  not  consider  the  primary  losses 
which  might  cause  different  voltages  on  the 
different  transformers.  Similar  ealculations 
can,  however,  be  made  for  them  ^^d  it  is 
probable  that  the  results  would  be  similar  to 
those  for  the  secondary  and  warrant  large 
enough  wire  to  offset  the  losses.  At  any  rat^ 
a practical  remedy  is  to  get  a great  enough 
load  density  so  that  the  primary  lengths  from 
the  first  to  the  last  transformer  on  a circuit 
are  short,  and  it  is  then  found  with  the 
“tree”  system  that  there  is  almost  no 
difference  of  voltage  on  the  different  trans- 
In Table  XIV  the  load  is  fixed  at  30  kw. 

It  is  interesting  as  another  general  problem 
to  determine  at  what  load  the  advantage 
turns— say  from  No.  6 to  No.  4 wire,  when 
the  loads  are  in  use  three  hours  per  day.  ims 
is  determined  in  Table  XV,  which  is  similar 
to  Table  XIV,  except  that  only  two  sizes 
of  wire  are  eonsidered,  and  the  tme  is  • 
constant  at  three  hours  per  day,  while  the 
load  is  varied  from  1 to  30  kw. 

Table  XV  shows  plainly  that  with  a loaa 
of  7)4  kw.  or  less  the  No.  6 wire  is  the  rnore 
economical,  while  if  the  load  is  increased  to 
10  kw.  or  above,  the  No.  4 wire  is  n^ore 


iU  KW.  U1  dUvJVC,  ^ ^ j +. 

economical.  It  is  also  interesting  to  find  that 

. 1 • r*o  I 


economical,  lu  lo  aiou  --  . 

the  voltage  loss  for  this  maximum  economical 
load  is  only  1.8  per  cent  or  a variation  ol  no 
more  than  0.9  per  cent  from  the  mean  vame  | 
This  table  should  be  extended  to  cover  all  ■ 
sizes  of  wire  for  aetual  use,  but  the  principle 
is  the  same  and  extension  here  is  not  con- 
sidered necessary.  _ • j 

Next,  it  is  interesting  to  consider  the 
practical  matter  of  replacing  small  wire  with 
larger  when  the  load  has  increased  enough 
to  require  it.  This  will  be  done  by  means  of 
the  tables  on  the  original  cost  of  wire  and 
credit  for  removal  of  wire  when  replaced  by 
larger.  (Tables  VIII  and  IX.) 

The  case  taken  for  a sample  calculation 
will  be  that  of  the  erection  of  No.  6 wire  to 
carry  its  full  capacity  of  7)4  kw.  and  later 
changing  it  to  No.  ^ when  the  load  requires. 
The  question  is  to  find  how  much  time 


PRACTICAL  ECONOMIES  IN  DISTRIBUTION 


1173 


must  elapse  between  the  original  installation 
and  the  date  of  increase,  in  order  to  make  it 
economical  to  erect  the  No.  G wire  and  later 
change  it  to  No.  0.  The  No.  6 wire  carrying 
73^  kv-a.  for  three  hours  per  day  (Table  XV) 
costs  $26.20  per  year. 

A similar  secondary  of  No.  0 wire  carrying 
lYl  kv-a.  with  a 73^-kv-a.  transformer  costs 
$27.45  per  year,  made  up  as  follows: 


Fixed  charges  for  transformer $14.60 

Fixed  charges  for  secondary  lines.  ...  1 1.80 


Transformer  copper  loss  0.120  kw. 
Secondary  power  loss 

(0.2S4  per  cent) 0.0213  kw. 

Total 0.1413  kw. 


Cost  of  0.1413  kw.  3 hours  per  day.  . 1.05 

Total $27.45 


Table  XV 

ANNUAL  CHARGES  AGAINST  A THREE-WIRE  SECONDARY  SYSTEM,  1000  FT.  LONG 
AND  CONSISTING  OF  NO.  6 OR  NO.  4 WIRE,  SHOWING  LOAD  POINT  AT  WHICH 
ECONOMY  TURNS  FROM  ONE  TO  THE  OTHER.  LOAD  IN  USE  3 HOURS 
PER  DAY  AND  DISTRIBUTED  UNIFORMLY  OVER  LENGTH  OF  LINE. 

95  PER  CENT  POWER-FACTOR 


224  Volts  Delivered;  Rate,  2 Cents  per  Kw-Hr. 


Trans- 

former 

Size 

Kv-a. 

1 

Annual 

Cost 

Trans- 

former 

NO.  6 

WIRE 

NO.  4 WIRE 

Fixed 

Charge 

Total 

Fixed 

Charges 

Operating 

Cost 

Total 

Fixed 

Charge 

Total 

Fixed 

Charges 

Operating 

Cost 

Total 

1.0 

$5.20 

$7.10 

$12.30 

$0.75 

$13.05 

$8.20 

$13.40 

.$0.60 

$14.00 

2.0 

7.20 

1 7.10 

14.30 

1.20 

15.50 

8.20 

15.40 

1.20 

16.60 

3.0 

9.25 

7.10 

16.35 

1.80 

18.15 

8.20 

17.45 

1.65 

19.10 

4.0 

11.10 

7.10 

18.20 

2.40 

20.60 

8.20 

19.30 

2.25 

21.55 

5.0 

12.10 

7.10 

19.20 

3.00 

22.20 

8.20 

20.30 

2.85 

23.15 

7.5 

14.60 

7.10 

21.70 

4.50 

26.20 

8.20 

22.80 

3.75 

26.55 

10.0 

19.20 

7.10 

26.30 

6.90 

33.20 

8.20 

27.40 

5.55 

32.95 

15.0 

25.45 

7.10 

32.55 

14.40 

46.95 

8.20 

33.65 

9.45 

43.10 

20.0 

31.25 

7.10 

38.35 

19.80 

58.15 

8.20 

39.45 

14.70 

54.15 

25.0 

37.25 

7.10 

44.35 

29.70 

74.05 

8.20 

45.45 

21.00 

66.45 

30.0 

41.30 

7.10 

48.40 

39.30 

87.70, 

8.20 

49.50 

24.00 

73.50 

Table  XVI 

SHOWING  DERIVATION  OF  OPERATING  COSTS  IN  TABLE  XV,  GIVING  OPERATING 
COST  FOR  TRANSFORMER  AND  SECONDARY  FOR  1 YEAR  WITH  USE  OF 
1 HOUR  PER  DAY.  RATE,  2 CENTS  PER  KW-HR. 


TRANSFORMER 

NO.  6 WIRE 
POWER  LOSS 

NO.  4 WIRE 
POWER  LOSS 

Size 

Kv-a. 

Copper 
Loss 
in  Kw. 

Per  Cent 

Kw. 

Total 

Kw. 

Cost 

Per  Cent 

Kw. 

Total 

Kw. 

Cost 

1.0 

0.030 

0.15 

0.0015 

0.0315 

$0.25 

0.095 

0.0010 

0.031 

$0.20 

2.0 

0.050 

0.30 

0.0060 

0.056 

0.40 

0.19 

0.0038 

0.054 

0.40 

3.0 

0.070 

0.45 

0.0135 

0.083 

0.60 

0.29 

0.0087 

0.079 

0.55 

4.0 

0.085 

0.61 

0.0244 

0.109 

0.80 

0.38 

0.0152 

0.100 

0.75 

5.0 

0.095 

0.76 

0.0380 

0.133 

1.00 

0.48 

0.0240 

0.129 

0.95 

7.5 

0.120 

1.14 

0.0854 

0.205 

1.50 

0.71 

0.0542 

0.174 

1.25 

10.0 

0.160 

1.52 

0.152 

0.312 

2.30 

0.95 

0.095 

0.2.55 

1.85 

15.0 

0.220 

2.28 

0.342 

0.662 

4.80 

1.43 

0.214 

0.434 

3.15 

20.0 

. 0.295 

3.03 

0.607 

0.903 

6.60 

1.90 

0.380 

0.675 

4.90 

25.0 

0.355 

3.80 

0.950 

1.355 

9.90 

2.48 

0.620 

0.975 

7.00 

30.0 

0.430 

4.55* 

1.37 

1.80 

13.10 

2.86 

0.860 

1.090 

8.00 

1174 


GENERAL  ELECTRIC  REVIEW 


Therefore  the  No.  0 wire  costs  but  $1.25 
more  per  year  than  the  No.  6 wire. 

To  change  from  No.  6 to  No.  4 wire  and 
from  a 734  kv-a.  to  a 30  kv-a.  transformer 
involves  charges  against  the  expense  account 
(Tables  VIII,  IX  and  X)  of, 

Changing  wire 

Changing  transformer 

Total $38.50 


To  change  from  a 734  kv-a.  to  a 30  kv-a. 
transformer  in  connection  with  the  No.  0 
wire  costs  $6.00.  The  difference  of  these 
charges  to  expense  is  $32.50.  This  figure  is  to 
be  compared  to  the  difference  of  $1.25  in 
operating  costs  for  the  period  previous  to  the 
change.  If  $32.50  is  divided  by  $1.25  it  is 
found  that  unless  the  smaller  load  is  in  use 
over  26  years  before  the  increase  comes,  it 
would  have  been  more  economical  to  erect 


the  No.  0 wire  originally. 

These  figures  are  most  startling.  Yet  they 
are  only  extreme  in  the  fact  that  if  any  other 
combination  is  chosen  the  period  will  be 
longer  instead  of  shorter.  They  do  point  out 
very  clearly  the  necessity  of  working  up 
tables  similar  to  these,  using  absolutely  the 
most  reliable  information  at  hand,  and  the 
extension  of  all  these  calculations  to  cover 
concentrated  and  other  distributions  of  mad^ 
as  well  as  the  case  of  uniformly  distributed 


loads  here  used. 

There  is  another  saving  that  could  be  made 
by  using  several  sections  of  the  No.  0 wire 
together  till  the  load  increased  to  an  extent 
to  require  separate  transformers.  This  would 
be  equivalent  to  “closing  through_  the 
secondaries  on  one  of  the  main  streets  m rig. 
4 and  omitting  one  of  the  transformers  on 
this  street.  It  could  then  be  sectionalized, 
in  the  light  of  greater  information  on  the  load, 
at  a future  date.  In  this  connection  it  is 
interesting  to  note  that  if  an  extreme  load 
came  on  at  any  point  the  transformer  could 
be  placed  directly  at  that  point  and  the  load 
would  not  affect  the  general  capacity  of  the 
secondary  in  the  slightest  degree. 


EFFECT  OF  ECONOMIES  ON 
COMMERCIAL  POLICY 
The  economies  that  can  be  practised  if 
the  future  load  is  known,  as  has  been  shown 
in  the  previous  sections,  are  so  obvious  that 
the  commercial  policy  that  they  dictate  fol- 
lows without  argument.  The  engineer  can 
build  lines  very  economically  if  he  is  allowed 
to  do  it  in  large  sections  at  a time,  and  if  the 
curve  of  the  predicted  growth  of  load  is  known. 

Therefore,  the  first  step  is  to  take  a large 
section  or  even  one  street  for  three  or 
blocks  and  determine  the  growth  of  load  and 
lay  out  an  economical  distribution  to  cover 
this;  then,  send  the  contract  agent  to  secure 
the  first  contract.  As  soon  as  this  has  been 
done  build  the  whole  distribution  system  and 
leave  it  to  the  contract  agent  to  come  up  to 
the  mark  set  for  him.  He  will  have  no  excuses 
of  high  service  costs  or  length  of  time  to  run 
service,  and  will  simply  have  to  hustle. 
Incidentally,  he  will  be  reduced  from  his  pres- 
ent high  place  as  the  man  who  brings  the  new 
life  blood  into  the  Company  and  will  become 
simply  a hard-working  part  of  the  machine.  , 

It  would  be  possible  to  write  at  length  on  ^ 
the  methods  for  determining  the  growth  of 
load  curve  and  the  sections  of  a property  first 
to  be  treated, but  that  is  a detail  that  can  easily 
be  worked  out  if  the  general  plan  is  adopted.  ! 

CONCLUSION  . , 

In  conclusion,  particular  attention  is  drawn  ( 
to  the  fact  that  this  is  but  the  beginning  ■ 
of  the  solution  of  the  great  problem  of  aerial 
distribution.  The  problem  of  underground 
lines  needs  treatment  in  a similar  manner,  only  ^ 
perhaps  more  urgently,  since  the  investment  is  ' 
much  greater.  The  comparison  of  overhead 
and  underground  lines  is  exactly  similar,  | 
only  probably  even  more  startling  in  some  of  i 

its  results.  I 

Let  all  concerned  in  any  way  in  distribution! 
bear  these  few  facts  in  mind  and  make  all  ^ 
their  work  and  records  conform,  so  that  in  ^ 
the  near  future  the  rational  solution  of  this  i 
ever-present  problem  of  the  central  station^ 
may  be  reached. 


1175 


THE  SUCCESSFUL  OPERATION  OF  A TELEPHONE  SYSTEM 
PARALLELING  HIGH  TENSION  POWER  LINES 

By  Charles  E.  Bennett 

Electrical  Engineer,  Georgia  Railway  & Power  Company 

The  author  describes  the  successful  installation  of  a telephone  line  on  the  towers  of  the  Georgia  Railway 
& Power  Company’s  Tallulah  Falls  110,000-volt  transmission  line.  The  fine  degree  of  potential  balance 
between  the  two  wires  of  the  telephone  line,  necessary  for  satisfactory  communication,  was  obtained  by 
transposing  the  wires  at  every  tower  and  by  thorough  insulation.  Drainage  coils  are  connected  between  the 
wires  and  to  ground  to  relieve  the  line  of  low  frequency  high  potential  stresses,  while  high  frequency  surges 
are  discharged  through  vacuum  type  lightning  arresters,  supplemented  by  horn  gaps.  A large  number  of 
tests  were  conducted  on  this  line  to  determine  the  effects  produced  by  different  arrangements  of  apparatus, 
and  the  results  are  given  in  the  text  and  in  the  accompanying  oscillograms. — Editor. 


The  problem  of  locating  private  telephone 
lines  on  the  steel  towers  of  high  voltage  power 
lines  instead  of  carrying  them  on  a separate 
pole  line  is  one  that  has  been  under  discussion 
for  some  time,  and  many  of  the  larger  com- 
panies have  abandoned  the  use  of  a telephone 
line  carried  on  the  towers  on  account  of  the 
many  troubles  occasioned  by  this  arrange- 
ment. 

When  telephone  lines  parallel  high  tension 
transmission  lines  they  are  subjected  to 
influences  which  may  under  certain  conditions 
interfere  with  the  proper  transmission  of 
speech.  This  interfering  influence  is,  in  all 
cases,  due  to  the  static  induction  from  the 
high  tension  transmission  line.  Under  normal 
operating  conditions,  i.e.,  with  fairly  well 
balanced  three-phase  circuits,  this  influence 
will  be  slight;  but  with  abnormal  operating 
conditions  on  the  transmission  line,  the  effect 
created  on  a telephone  line  may  increase  to 
such  an  extent  as  to  become  destructive. 
In  addition  to  these  influences  the  telephone 
line  is  subjected  to  disturbances  occasioned 
by  lightning  discharges,  which,  however,  are 
very  similar  in  character  .to  the  effects  created 
by  abnormal  conditions  on  the  transmission 
line,  such  as  those  occasioned  by  switching 
with  unbalanced  phases,  arcing  grounds,  etc. 

Under  normal  operating  conditions  the 
effect  of  the  static  induction  upon  the  two 
wires  of  the  telephone  line  is  practically  the 
same,  with  the  result  that  the  two  wires  will 
assume  a definite  potential  with  regard  to 
earth.  With  a well  insulated  and  properly 
transposed  metallic  line,  the  potentials  of 
each  wire  against  ground  will  be  nearly  alike, 
and  hence  there  will  be  no  difference  of 
potential  between  the  two  wires  themselves. 
.In  telephone  work,  however,  even  the  smallest 
difference  of  potential  between  the  wires  will 
create  a flow  of  current  through  the  telephone 
receiver.  This  current,  being  alternating, 
produces  a noise  in  the  receiver  which  may  be 
loud  enough  to  render  talking  impossible. 


The  higher  the  voltage  of  a transmission  line 
and  the  closer  the  telephone  line  to  the  trans- 
mission line,  the  more  prominent  will  be  the 
noise  in  the  telephone,  with  a slightly  un- 
balanced telephone  line.  As  this  disturbing 
current  is  due  to  a difference  of  potential. 


Fig.  1.  Photograph  of  a Standard  Line  Tower  of  the 
Georgia  Railway  85  Power  Co.,  Showing  the  Power 
Wires  and  the  Telephone  Wires  and 
Their  Transposition 

it  is  obvious  that  the  noise  in  the  receiver  is 
in  a measure  independent  of  the  absolute 
value  of  the  voltage  of  each  line  to  ground, 
and  that  it  cannot  be  eliminated  unless  the 
voltage  on  both  wires  be  made  exactly  alike. 
This  condition,  which  is  termed  “balanced,” 
is  realized  by  properly  insulating  and  trans- 


1176 


GENERAL  ELECTRIC  REVIEW 


posing  the  telephone  wires.  The  larger  the 
number  of  transpositions  per  mile,  the  more 
nearly  will  the  potential  on  the  wires  be 
equalized ; and  the  better  the  insulation  of  the 
lines,  the  less  will  there  be  a chance  for  a 


Fig.  2.  Dimensioned  Drawing  Showing  the  Location  of  the 
Power  and  Telephone  Wires  on  Tower 


“leak”  (to  ground),  causing  a drop  of  po- 
tential on  that  particular  wire,  with  the  sub- 
sequent result  of  unbalancing  the  line  and 
rendering  it  noisy. 

From  the  above  it  will  be  seen  that  so  tar 
as  the  noise  of  the  line  is  concerned  it  can  be 
kept  within  any  limit,  provided  the  telephone 
line  is  properly  transposed  and  well  insulated. 
On  the  other  hand,  it  will  be  seen  that  the 
existing  potential  between  telephone  wires 
and  ground,  by  reaching  high  potential  values, 
may  not  necessarily  impair  the  transmission 
of  speech,  but  will  seriously  strain  the 


insulation  of  the  instruments  and  make  their 
use  dangerous. 

*The  transmission  system  of  the  Georgia 
Railway  & Power  Company  consists  of  a 
double  4/0  circuit  from  Tallulah  Falls  to 
Atlanta,  a distance  of  90  miles,  with  double 
2/0  circuits  extending  northward  to  Lindale 
-and  southward  to  Newnan  from  Atlanta. 
The  line  from  Atlanta  to  Lindale  is  about 
75  miles  in  length,  while  the  line  to  Newnan 
is  about  40  miles.  All  of  these  lines  are 
operated  at  from  110,000  volts  to  120,000 
volts  at  60  cycles. 

This  system  is  paralleled  by  a single  two- 
wire  telephone  circuit  located  about  10  feet 
(diagonally)  below  the  bottom^  power  con- 
ductor and  carried  on  the  horizontal  angle 
iron  which  forms  a part  of  the  tower. 

The  original  layout  was  made  with  pm 
insulators  of  11,000-volt  design,  but  the  many 
induced  surges  or  steep  front  waves  punc- 
tured them  with  such  remarkable  rapidity 
that  is  was  decided  more  insulation  or  punc- 
ture-proof quality — was  necessary.  From 
a construction  standpoint  it  was  found  most 


Fig.  3.  Telephone  Booth  Connected,  Showing  Discon- 
necting Switch  and  Horn  Gaps 


convenient  to  re-insulate  the  line  with  sus- 
pension disks.  It  has  been  found  that  one 
suspension  unit  will  withstand  most  of  the 


*A  full  description  of  Tallulah  development  of  tte 

Georgia  Railway  & Power  Company  will  be  found  m the  June 
and  July,  1914,  issues  of  the  Review. 


( 

I 

i 


THE  SUCCESSFUL  OPERATION  OF  A TELEPHONE  SYSTEM 


1177 


electrical  stresses,  but  in  order  to  secure 
perfect  continuity,  two  were  used.  The 
telephone  wires  are  spaced  at  three-foot 
centers,  the  wire  itself  being  No.  4 copper 
clad,  of  30  per  cent  conductivity,  drawn  from 
400  lb.  ingots  in  lengths  of  about  half  a mile 
to  minimize  the  number  of  joints.  All  joints 
are  made  with  special  “figure  eight”  splicing- 
sleeves  about  nine  inches  long. 

The  reason  for  using  wire  of  this  size  was 
that  it  might  be  strung  parallel  to  the  power 
conductors  and  still  be  able  to  withstand  a 
loading  of  about  three-quarters  of  an  inch 
of  ice  without  exceeding  the  elastic  limit. 

Transpositions  are  made  on  all  towers, 
which  average  about  nine  or  ten  to  the  mile. 
The  wires  are  supported  by  suspension  insu- 
lators on  each  side  of  the  tower,  two  insulators 
being  used  at  each  point  of  support,  and 
transpositions  made  with  long  and  short 
loops  between  the  insulators  located  on 


Fig.  4.  Front  View  of  the  Telephone  and  Its  Protective 
Equipment  as  Installed 


opposite  sides  of  the  tower.  The  transposi- 
tions are  all  made  with  the  same  clockwise 
twist,  so  as  to  make  a running  transposition. 

At  intervals  of  four  miles,  telephone  booths 
are  located.  They  are  simply  frame  buildings 
of  the  knockdown  type,  about  four  feet  square. 


with  a 22,000-volt  switch  of  special  con- 
struction on  the  roof.  This  switch  is  made 
with  horn  gaps  to  ground,  set  at  approxi- 
mately three-eights  of  an  inch,  and  the  two 
poles  are  operated  simultaneously  by  means 
of  a hand  lever  inside  the  booth.  An  insulated 


Fig.  5.  Side  View  of  the  Apparatus 
shown  in  Fig.  4 


platform  is  provided  in  the  booth  on  which 
the  operator  may  stand  while  throwing  the 
switch  that  cuts  the  station  in  multiple  with 
the  line.  This  switch  is  opened  as  soon  as 
the  operator  finishes  his  conversation.  In 
otherwords,  the  telephones  in  the  booths  are 
only  connected  to  the  line  during  the  time 
they  are  in  actual  use,  and  the  equipment  is 
therefore  not  endangered  by  surges  or  light- 
ning along  the  line,  nor  is  the  talking  impaired 
by  having  a number  of  stations  in  multiple. 

At  numerous  places,  convenient  to  working 
crews,  the  telephone  line  is  sectionalized  to 
facilitate  the  location  of  trouble,  and  at  the 
intermediate  substations  22,000-volt  double- 
pole switches  are  used  for  this  purpose. 

Specially  designed  receiving  and  sending 
equipment  is  located  at  the  power  house  and 
substations,  which  is  standard  for  all  stations. 
It  comprises  a horn  gap  to  ground  mounted 
on  a bracket  at  the  entrance  to  the  building, 
and  a 50-turn  air  choke  coil;  the  line  then 


1178 


GENERAL  ELECTRIC  REVIEW 


passing  through  20, 000- volt  entrance  bushings 
to  the  interior,  where  a specially  designed 
double-pole  fused  switch  is  inserted.  From 
this  switch  the  line  is  connected  through  a 
horn  gap  and  vacuum  arrester  to  a one  to  one 


Fig.  6.  Connection  Diagram  of  a Telephone  Located 
at  a Station 


Type  Y-109-B  insulating  transformer,  which 
in  turn  is  connected  to  the  telephone  instru- 
ment. 

The  usual  way  to  relieve  telephone  lines  of 
high  potential  is  to  bridge  a so-called  bleeding 
or  drainage  coil  across  the  line.  Considerable 
experimenting  was  done  with  drainage  coils 
on  this  line,  and  it  was  found  that  the  ordinary 
type  was  not  of  sufficient  carrying  capacity. 
Sizes  of  1 kw.,  3.5  kw.,  and  5 kw.  were  soon 
destroyed  and  then  a 15  kw.  2200-1100/- 
220-110  Type  H lighting  transformer  was 
installed,  which  has  given  very  good  results. 
The  telephone  line  is  connected  to  the 
terminals  of  the  2200-volt  winding  and  the 
middle  point  of  this  winding  connected  to 
ground.  The  secondaries  are  then  left  open 
circuited.  This  arrangement  will  offer  a high 
inductive  resistance  to  the  talking  currents, 
but  a very  low  ohmic  and  negligible  inductive 
resistance  to  the  flow  of  current  from  the  two 
wires  to  ground,  owing  to  the  fact  that  the 
simultaneous  discharge  from  the  wires  through 
the  coils  to  ground  will  neutralize  the  mag- 
netic effects.  This  bleeding  coil  becomes  an 


effective  outlet  for  all  low  frequency  currents 
indueed  from  the  transmission  line. 

Sudden  changes  in  the  transmission  line, 
like  switching,  arcing  grounds,  lightning 
discharges,  etc.,  have  all  the  same  effect 
upon  a balanced  telephone  line,  namely, 
to  charge  the  two  wires  suddenly  to  a very 
high  potential.  Owing  to  the  rapidity,  or 
in  other  words,  the  high  frequency  with 
which  these  charges  are  induced  on  a telephone 
line,  the  small  inductance  of  the  bleeding 
coil,  no  matter  how  accurately  balanced, 
is  not  sufficient  to  prevent  these  charges 
from  flowing  to  ground,  and  therefore  another  , 
apparatus  is  required  which  will  act  as  an  ' 
outlet  for  these  particular  disturbances,  j 
It  has  been  found  that  the  vacuum  type  ! 
arrester  is  best  suited  for  this  service. 
This  arrester  consists  of  two  electrodes 
enclosed  in  a partially  exhausted  metal  tube 
and  connected  across  the  line.  This  arrester 
is  very  sensitive  to  charges  of  high  fre- 
quency and  will  begin  to  discharge  freely 


Fig. 


Line  Wires 


vvwwww  One  to  One 
AMVWWVA,  Transformer 


7.  Connection  Diagram  of  a Telephone  Located 


in  a Booth 


as  soon  as  the  voltage  on  the  lines  reaches 
about  300  volts.  The  peeffiiar  advantages 
of  these  arresters  lie  in  the  fact  that  the  dis- 
charge occurs  gradually  instead  of  dis- 
ruptively,  and  these  discharges  have  no  ill 


THE  SUCCESSFUL  OPERATION  OF  A TELEPHONE  SYSTEM 


1179 


effect  upon  the  electrodes,  leaving  the  line 
perfectly  clean  and  balanced.  It  is  advis- 
able to  place  fuses  in  circuit  to  protect  this 
arrester  from  destruction  should  the  dis- 
charges, for  some  reason  or  other,  exceed  the 
safe  value  for  which  it  is  built.  The  large 
gaps  or  horns,  being  set  at  three-eighths  of 
an  inch,  form  a sort  of  rough  protection  to  all 
the  equipment,  should  it  be  subjected  to  very 
high  momentary  potentials. 

The  station  equipment  of  this  system  was 
tested  by  impressing  60,000  volts  on  it, 
which  resulted  only  in  the  blowing  of  a fuse. 

Calculations  were  made  to  determine  the 
potential  of  the  line  against  ground  by  use 
of  the  following  formula,  which  is  offered  for 
those  interested  in  figuring  out  new  lines: 

Let  A,  B and  C represent  the  three  con- 
ductors of  a three-phase  power  circuit,  and  5 
and  T the  conductors  of  the  telephone  circuit. 

Let  Eo  be  the  voltage  between  each  wire 
of  the  power  circuit  and  ground. 

Let 

r = radius  of  power  conductor  in  inches. 

a = distance  in  inches  between  A and 

ground.  (Av.) 

b = distance  in  inches  between  B and 

ground.  (Av.) 

c = distance  in  inches  between  C and 

ground.  (Av.) 

5 = distance  in  inches  between  5 and 

ground.  (Av.) 

t = distance  in  inches  between  T and 

ground.  (Av.) 

Then 


, 2a  — r 


for  s in  the  above  formulae.  (From  Ferguson’s 
“Elements  of  Electrical  Transmission.’’) 

By  the  use  of  this  formula  a theoretical 
induced  potential  of  5700  volts  for  the  above 
line  was  obtained.  Tests  have  subsequently 
been  made  to  ascertain  the  actual  value  of 
this  induced  potential. 

With  one  power  line  energized  (the  power 
conductors  being  on  nine-foot  centers  in  a 
vertical  plane),  an  induced  potential  reading 
of  5600  volts  from  line  to  ground  was  ob- 
tained. As  the  high-voltage  system  has  its 
neutral  grounding  at  the  power  house,  the 
voltage  between  each  power  line  and  ground 
was,  of  course,  63,500  volts.  The  current  in 
the  drainage  coil  neutral  was  4.47  amperes 
at  the  time  the  above  readings  were  obtained. 

In  order  to  ascertain  the  maximum  poten- 
tials that  could  be  induced  on  this  line,  the 
following  tests  were  made  and  results  ob- 
tained as  indicated: 

With  the  top  wire  of  one  power  circuit 
charged,  an  induced  potential  reading  of 
5100  volts  was  obtained  between  telephone 
line  and  ground. 

With  the  middle  wire  of  one  power 
circuit  charged,  the  induced  potential 

reading  was  found  to  be  7200  volts. 

With  the  bottom  wire  of  one  power 
circuit  charged,  the  induced  potential 

reading  was  found  to  be  10,000  volts. 

With  the  top  wire  of  each  power  circuit 
charged,  the  induced  potential  reading 
was  found  to  be  9300  volts. 

With  the  middle  wire  of  each  power 
circuit  charged,  the  induced  potential 

reading  was  found  to  be  13,100  volts. 

With  the  bottom  wire  of  each  power 
circuit  charged,  the  induced  potential 

reading  was  found  to  be  18,200  volts. 


Eq 


ec  = Eo 


log 

log 

log 

log 


5-f-5 
b — s 
2b  — s 
r 

C + 5 

c — s 
2c  — r 


and 

^s  = Vea^+eb‘‘+eJ‘—  (eaeb+eaec+ebec) 

where  e is  equal  to  potential  of  wire  5 against 
ground . Potential  of  wire  7 against  ground  may 
be  found  by  a similar  process,  substituting  t 


All  of  the  above  readings  were  taken  with 
a 100  to  1 potential  transformer  and  indi- 
cating voltmeter,  the  drainage  coil  being 
disconnected.  Tests  were  then  made  with 
the  drainage  coils  connected  across  the  line 
at  Gainesville  and  Atlanta  and  three  wires  of 
north  circuit  excited.  Figures  give  current 
in  ground  connection  of  drainage  coils. 

Line  voltage 110,000  50,000 

Current  in  ground  connection  of 

drainage  coil  at  Atlanta,  Ga.  1.0  amp.  0.6  amp. 
Current  in  ground  connection  of 
drainage  coil  at  Gainesville, 

Ga 2.6  amp.  1.15  amp. 

Current  in  ground  connection  of 
drainage  coil  at  Gainesville 
with  drainage  coil  at  Atlanta 
disconnected  from  line 3.55  amp.  1.50  amp. 


1180 


GENERAL  ELECTRIC  REVIEW 


Fig.  8.  Upper  Curve:  Line  Potential  Phase  1.  Lower  Curve: 
Current  in  Ground  Connection  of  Drainage  Coil 


Fig.  9.  Upper  Curve:  Line  Potential  Phase  3.  Lower  Curve: 
Current  in  Ground  Connection  of  Drainage  Coil 


Fig.  10.  Upper  Curve:  Current  in  One  Wire  of  Telephone 

Line  0.8  amp.  Middle  Curve:  Current  in  Other  Wire 
of  Telephone  Line  0.8  amp.  Lower  Curve:  Cur- 
rent in  Ground  Connection  of  Drainage  Coil 
1.6  amp.  Record  taken  while  Lightning 
Arresters  were  being  charged 


X 

f'  V 


/ 


i ‘ : 

^ / 


Fig.  11.  Upper  Curve:  Line  Potential  Phase  2.  Lower 
Curve:  Current  in  Ground  Connection  of  Drainage  Coil 


f / '' 

■A  J 

/ 

\ 

1 / 

-t 

. ■'  * f • 

A-/ 

A ./ 

A\  / 

V' 

■ U '/ 

\ ,/  ■ 

Fig.  12.  Upper  Curve:  Line  Potential  Phase  3 to  Ground 

63,500  volts.  Lower  Curve:  Induced  Potential 

on  Telephone  Line  3500  volts 


\ 

...A^  ^ 

\\ 

\ ■ 

V 

* A 

i : -9 

^ A 

. A / 

A / 

V;  / 

■ 

V 

-T. 

A.  J 

Fig.  13.  Upper  Curve:  Voltage  on  Phase  3 of  Power  Line, 

while  Arresters  were  being  charged.  Lower  Curve: 
Current  in  Groimd  Connection  of  Drainage 
Coil  on  Telephone  Line 


OSCILLOGRAPH  RECORDS  OF  INDUCED  WAVES 


THE  SUCCESSFUL  OPERATION  OF  A TELEPHONE  SYSTEM 


1 181 


Fig.  14.  Upper  Curve:  Potential  of  Phase  3 Power  Line 

to  Ground.  Lower  Curve:  Induced  Potential 
on  Telephone  Circuit  5600  volts 

The  voltage  from  teleph^e  line  to  ground 
with  three  wires  of  the  north  circuit  excited 
to  the  line  voltage  shown,  and  with  drainage 
coils  connected  at  both  Atlanta  and  Gaines- 
ville, was  as  follows: 


Line  voltage 110,000  volts  50,000  volts 

At  Atlanta 0.0  volts  0.0  volts 

At  Gainesville 31.0  volts  18.0  volts 

At  Tallulah 234.0  volts  100.0  volts 


The  following  figures  give  the  voltage  from 
telephone  line  to  ground  with  three  wires 
of  the  north  circuit  excited  to  the  line  voltage 
shown,  and  drainage  coil  connected  at 
Gainesville  but  disconnected  at  Atlanta: 

Line  voltage • 110,000  volts  50,000  volts 

At  Atlanta 158.0  volts  70.0  volts 

At  Gainesville 41.0  volts  20.0  volts 

At  Tallulah 240.0  volts  105.0  volts 

Three  drainage  coils  are  now  installed  on 
the  Atlanta-Tallulah  line,  one  each  at  Gaines- 
ville, Tallulah  and  Atlanta,  and  the  talking 
over  the  line  is  excellent. 

If  the  following  principles  are  adhered  to 
in  the  construction  of  a telephone  line, 
paralleling  a high  tension  line,  successful 
operation  should  follow: 

1 .  The  telephone  line  should  be  thoroughly 
insulated  from  ground,  allowing  a liberal 
factor  of  safety,  as  insulation  is  paramount. 


Fig.  15.  North  Circuit  Charged.  Voltage  Curve:  Voltage 
between  Telephone  Line  and  Ground  5100  volts 


Fig.  16.*  Potential  Wave  on  Telephone  Line  with  One  Circuit 
of  Power  Line  Charged.  Voltage  between  Tele- 
phone and  Ground  4500  volts 

2.  The  line  should  be  constructed  with 
as  few  joints  as  possible. 

3.  The  ohmic  resistance  of  the  line  should 
be  as  low  as  possible,  so  as  not  to  decrease 
the  intensity  of  the  talking  waves. 

4.  A perfect  potential  balance  should  be 
obtained  between  wires. 

5.  Transposition  should  be  made  at  every 
tower,  so  as  to  maintain  equal  potential 
between  the  two  telephone  wires  and  ground. 


* From  this  oscillograph  record,  which  was  taken  on  a tele- 
phone line  strung  parallel  to  110,000-volt  power  line  for  a 
distance  of  fifty  miles  but  carried  on  a separate  pole  line,  it  can 
be  seen  that  the  number  of  harmonics  is  considerably  greater 
than  when  telephone  line  is  strung  on  towers  carrying  power  lines. 


1182 


GENERAL  ELECTRIC  REVIEW 


THE  VENTILATION  OF  ALLEGHENY  SUMMIT  TUNNEL, 
VIRGINIAN  RAILWAY 

By  F.  F.  Harrington 

Engineer  of  Structures,  The  Virginian  Railway  Company 

The  ventilating  equipment  for  the  Allegheny  Summit  tunnel  is  located  at  the  eastern  portal,  and  was 
installed  for  the  purpose  of  driving  the  smoke  and  gases  emitted  by  engines  on  the  upgrade  or  westbound 
trip  ahead  of  the  train,  thus  relieving  the  train  crew  from  the  disagreeable  and  unhealthful  effects.  Trains 
in  the  opposite  direction  coast  on  the  downgrade,  with  the  locomotive  fires  banked,  and  therefore  no  provision 
has  been  made  for  ventilating  the  tunnel  during  the  passage  of  these  trains.  The  plant  will  ultimately  be 
automatic  in  operation,  and  the  control  apparatus  has  been  built  accordingly,  although  the  track  circuits 
have  not  yet  been  installed. — Editor. 


Allegheny  Summit  Tunnel  is  located  on  the 
Virginian  Railtvay,  277.6  miles  from  Norfolk, 
Va.,  between  Yellow  Sulphur  and  Merri- 
mac. 

Princeton,  W.  Va.,  340  miles  from  Norfolk, 
Va.,  is  the  assembling  yard  for  coal  mined  at 
points  west  and  north  along  the  main  line 
and  on  branch  lines.  At  this  point  long  trains 
are  made  up  and  sent  through  to  tidewater. 
The  maximum  eastbound  grade  from  Prince- 
ton to  Sewalls  Point,  with  two  exceptions,  is 
0.2  per  cent  compensated  for  curvature,  and 
the  maximum  westbound  grade  between  the 
same  two  points,  with  two  exceptions,  is  0.6 
per  cent  compensated.  The  exceptions  are 
at  Onley  Gap  and  Allegheny  Summit,  located 
respectively  3 and  62  miles  east  of  Princeton. 
A single  engine  hauls  80  loaded  cars  of  100,000 
pounds  capacity  from  Princeton  yard  to 
tidewater  without  assistance,  and  the  same 
engine  hauls  an  equal  number  of  empty  cars 
against  westbound  grades,  except  at  the 
summits  mentioned  above.  At  Allegheny 
Summit  a single  pusher  engine  is  used  between 
Whitethorne  and  Fagg,  hauling  80  loaded 
coal  cars  eastbound  on  a maximum  0.6  per 
cent  compensated  grade  from  Whitethorne  to 
the  summit,  a distance  of  ten  miles,  and  80 
empty  coal  cars  westbound  on  a maximum 
1.5  per  cent  compensated  grade  from  Fagg  to 
the  summit,  a distance  of  seven  miles. 

A typical  cross  section  of  Allegheny 
Tunnel  is  shown  in  Fig.  3.  The  alignment 
is  tangent  except  for  about  200  feet  at  the 
east  end,  which  is  on  a two-degree  curve, 
and  the  grade  is  1.22  per  cent  except 
for  about  1000  feet  at  the  west  end,  which 
is  on  a vertical  curve.  The  total  length 
between  portals  is  5176  feet  and  the  cross 
sectional  area  is  375  square  feet.  It  was  lined 
with  timber  throughout  when  constructed  in 
1908,  and  afterwards  concrete  footings  were 
constructed  and  two  sections  50  ft.  and  248  ft. 
long  were  lined  with  concrete.  The  remainder 
of  the  tunnel  was  lined  with  concrete  last 


year,  and  as  this  lining  contracted  the  sec- 
tional area  and  increased  the  heat  consider- 
ably, the  ventilation  of  the  tunnel  was  author- 
ized by  the  management  to  improve  the 
operating  conditions.  A brief  description  of 
the  ventilating  plant  follows: 

The  method  employed  for  the  ventilation  of 
the  tunnel  is  covered  by  patents  held  by 
Chas.  S.  Churchill  and  Chas.  C.  Wentworth, 
of  Roanoke,  Va.,  who  furnished  the  general 
plans  and  specifications  for  the  nozzle  and  the 
necessary  data  for  obtaining  bids  from  the 
fan  manufacturers.  The  plant  is  illustrated 
by  the  accompanying  photographs  and  plans. 
Figs.  1,  2,  and  3,  and  is  located  at  and  con- 
nected to  the  east  end  of  the  tunnel.  It  con- 
sists briefly  of  two  large  fans  operated  by  : 
electric  motors,  one  set  being  located  on  each 
side  of  the  track.  These  fans  force  air  through 
sheet  iron  ducts  between  the  fans  and  the  , 
nozzle,  and  then  through  the  nozzle,  the 
reduced  opening  of  which  gives  a high  veloeity 
to  the  air  through  the  tunnel.  The  smoke  and 
gases  from  the  westbound  engines  on  the  i 
ascending  grade  are  therefore  driven  ahead, 
thus  cleaning  the  tunnel  and  making  it  cool 
and  comfortable  for  the  trainmen.  The  east- 
bound  engines,  drifting  on  the  descending  j 
grade,  emit  little  smoke  and  gases,  and  it  is  j 
not  necessary  to  operate  the  fans;  although  j 
this  is  occasionally  done  to  clear  the  tunnel 
after  their  passage. 

The  ventilating  plant  was  designed  to 
deliver  a volume  of  590,000  cu.  ft.  of  air  per 
minute  through  the  nozzle,  whieh  has  an  j 
outlet  area  of  74  sq.  ft.;  this  corresponding 
to  a veloeity  of  air  in  the  tunnel  of  about  1600  j 
ft.  per  minute.  A thorough  investigation  I 
was  made  of  the  relative  economy  of  operation  ll 
by  steam  and  by  electricity,  and  of  the  con-  I 
struction  of  a power  plant  and  the  purchase  of  I 
power;  it  was  finally  decided  to  use  electric  | 
current  and  purchase  power  from  the  Appala- 
chian Power  Company,  which  operates  in 
that  locality. 


VENTILATION  OF  ALLEGHENY  SUMMIT  TUNNEL 


1183 


The  Appalachian  Power  Company  was 
organized  in  1911  for  the  purpose  of  develop- 
ing the  water  power  of  New  River  and  dis- 
tributing it  electrically  throughout  southwest 
Virginia  and  southern  West  Virginia.  It 
furnishes  electric  power  for  the  operation  of 
coal  mines  and  other  industrial  plants  in  those 
districts.  The  high  tension  transmission 
lines  operate  at  88,000  volts  and  feed  sub- 
stations at  various  points,  where  the  voltage 
is  lowered  for  distribution  through  secondary 
lines  to  the  various  power  consumers.  A 
special  high  tension  transmission  line  was 


were  manufactured  by  the  B.  F.  Sturtevant 
Company,  Hyde  Park,  Mass.  They  are  con- 
structed of  in.  steel,  IIG^^  in.  in  diameter, 
8034  width,  and  deliver  through  the 

nozzle  295,000  cu.  ft.  of  air  per  minute  when 
operating  at  195  r.p.m.  The  induction 
motors  are  of  the  slip-ring  type,  rated  300  h.p., 
three-phase,  60-cycle,  2200-volt,  514-r.p.m., 
and  drive  the  fans  by  means  of  Morse  silent 
chains,  spaced  5 ft.  6 in.  on  centers. 

The  switchboard  is  arranged  with  auto- 
matic starters  for  operating  the  motors  from 
track  circuits,  but  the  track  circuits  have  not 


View  Showing  Position  of  Ventilating  Equipment  and  Tunnel  Portal 


built  from  Radford,  Va.,  to  the  east  portal  of 
the  Allegheny  Summit  Tunnel,  where  a sub- 
station was  constructed  which  lowers  the 
voltage  to  2300  volts  for  the  operation  of  the 
ventilating  plant.  The  contract  for  electric 
power  provides  for  a primary  charge  per  kilo- 
watt of  maximum  demand,  and  a secondary 
charge  for  current  consumed  based  on  a slid- 
ing scale.  The  maximum  demand  and  the 
current  consumed  are  determined  by  suitable 
meters,  and  a minimum  annual  charge  is  made 
regardless  of  the  power  consumption. 

The  fans  are  of  the  multivane  type,  with 
single  inlet  and  top  horizontal  discharge,  and 


been  installed.  The  object  of  the  automatic 
control  is  to  make  the  plant  more  reliable  and 
to  reduce  the  cost  of  operation. 

The  switchboard  consists  of  one  main  line 
control  panel  and  two  automatic  motor 
starting  panels  mounted  on  pipe  supports. 
The  main  line  control  panel  consists  of  two 
three-pole  single-throw  oil  switches  with  auto- 
matic overload  and  no-voltage  release  trip- 
ping coils.  The  incoming  line  feeds  these 
switches  and  each  controls  the  current  to  one 
of  the  motor  starting  panels.  On  this  panel 
is  also  mounted  an  indicating  voltmeter  and 
ammeter,  which  shows  the  total  input  to  both 


1184 


GENERAL  ELECTRIC  REVIEW 


motors.  The  motor  starting  panels  each  com- 
prise two  current  limit  relays,  one  main  line 
double-pole  oil  emersed  contractor,  and  five 
double-pole  contractors  which  cut  out  the 
resistance  in  the  secondary  of  the  motors  in 
balanced  steps  and  thus  give  equal  fluctua- 
tions of  current  in  each  step.  All  of  the  con- 
trol apparatus  is  located  in  the  motor  house 
on  the  north  side  of  the  track,  and  the  two 
three-wire  lead-sheathed  cables  to  the  motors 
on  south  side  of  track  are  installed  under- 
ground in  6-in.  conduit.  The  motors  are 
protected  from  lightning  by  choke  coils  and 
multigap  type  lightning  arresters. 


sq.  ft.  measured  on  the  projection  at  right 
angles  to  the  axis  of  tunnel.  The  front  of  the 
nozzle  is  provided  with  openings  to  which  the 
air  ducts  from  the  fan  housings  are  connected. 
The  nozzle  is  thoroughly  braced  and  is  air 
tight.  It  was  manufactured  and  erected  by 
the  Roanoke  Bridge  Company,  Roanoke,  Va. 

The  air  ducts  between  the  fan  housing  and 
the  nozzle  are  made  of  3^-in.  sheet  steel  and 
braced  with  angle  irons.  Particular  attention 
was  given  to  the  construction  of  these  ducts 
and  the  fan  housing  in  order  to  prevent  exces- 
sive vibration  from  the  operation  of  the 
fans. 


Side  View  of  Ventilating  Equipment 


The  blowing  nozzle  is  constructed  of  steel, 
with  the  exception  of  the  inner  lining  which 
is  of  heart  long  leaf  yellow  pine,  tongued  and 
grooved  and  bolted  to  steel  girts.  It  is  made 
to  conform  to  the  dimensions  of  the  tunnel 
where  it  connects  to  the  portal,  and  is  50  ft. 
long  outside  the  tunnel.  The  inner  lining  is 
also  of  the  same  form  and  dimensions  as  the 
tunnel;  but  the  outer  lining,  made  of  j/g-in. 
steel  plates,  is  enlarged  in  the  form  of  a coni- 
cal surface  with  cross  sections  parallel  to  the 
inner  lining  from  a point  5 feet  from  the  portal 
to  the  face  of  the  nozzle.  The  minimum 
distance  between  the  inner  and  outer  linings 
at  a point  10  ft.  from  the  portal  is  1134  in.; 
and  the  area  of  the  contracted  opening  is  74 


The  foundations  for  the  ventilating  plant 
are  of  concrete  and  the  motor  houses  are  of 
reinforced  concrete  and  brick.  In  order  to 
save  expense  the  floors  of  the  motor  houses 
were  placed  about  8 ft.  above  the  top  of  the 
rail,  and  concrete  stairways  and  lookout 
platforms  are  provided  for  the  convenience 
of  the  operator.  The  motor  house  on  the 
north  side  of  the  track  is  larger  than  that  on 
the  south  side,  in  order  to  provide  room  for 
the  switchboard  for  both  motors.  The 
foundations  and  motor  houses  were  con- 
structed in  accordance  with  plans  furnished 
by  the  Railway  Company. 

The  ventilating  plant  was  put  in  operation 
April  1,  1914.  Anemometer  tests  were 


VENTILATION  OF  ALLEGHENY  SUMMIT  TUNNEL 


1185 


made,  which  showed  an  average  air  velocity 
in  excess  of  the  contract  requirements  and  an 
actual  power  consumption  of  about  600  h.p. 
Train  tests  indicated  that  a speed  of  from  14 
to  15  miles  per  hour  could  be  attained,  with  the 
smoke  driven  ahead  of  the  engines,  thus 
giving  good  ventilation  in  the  tunnel  under 
ordinary  operating  conditions.  A bulletin 
has  therefore  been  issued  to  limit  the  speed  of 
westbound  trains  to  14  miles  per  hour,  and  at 
this  rate  the  regular  freight  trains  will  not  be 
required  to  slow  down  in  going  through  the 


tunnel.  The  fans  operate  only  for  westbound 
trains,  and  the  time  of  running  is  ordinarily 
less  than  ten  minutes.  A train  dispatcher’s 
telephone  is  installed  in  the  motor  house  to 
enable  the  operator  to  keep  in  touch  with  the 
train  movements  in  both  directions  and  to 
communicate  with  the  Appalachian  Power 
Company  at  Bluefield,  through  the  dis- 
patcher’s office  at  Princeton,  in  case  of  cur- 
rent failure  or  for  any  other  reason.  The 
total  cost  of  the  ventilating  plant  was  about 
$30,000. 


Sectional  Views  of  Nozzle  and  its  Relation  to  Tunnel 


GENERAL  ELECTRIC  REVIEW 

THE  ELECTRIC  FIELD 


By  F.  W.  Peek,  Jr. 


Consulting  Engineer,  General  Electric  Company 


All  electrical  design  is  dependent  the'amS 

tSrfndVctivt'fff  ects  r?he""eKostaB^ 

e.ec.c  «e.a.-E..oK. 


In  order  that  electrical  energy  may  flow 
along  a conductor,  energy  must  be  stored 
in  the  space  surrounding  the  conductor.  This 
energy  must  be  stored  in  two  forms;  electro- 
magnetic and  electrostatic.  _ 

The  electromagnetic  energy  is  evinced  by 
the  action  of  the  resulting  stresses;  for 
instance,  the  repulsion  between  two  parallel 
wires  carrying  current,  the  attraction  o 
suspended  piece  of  iron  when  brought  near 
the^  wires,  or,  better  yet,  if  the  wires  are 
brought  up  through  a plane  of 
insulating  material,  _ and  this 
plane  is  dusted  with  iron  filings, 
and  gently  tapped,  the  filings 
will  form  in  eccentric  circles 
about  the  conductors.  These 
circles  picture  the  direction  of 
the  magnetic  lines  of  force  of 
the  magnetic  field.  This 
only  exists  when  current  is  flow- 
ing in  the  conductor.  Fig.  1 is 
an  experimental  plot  of  such  a 
field  made  by  placing  a sheet  of 
blueprint  paper  on  the  plane 
and  exposing  to  sunlight  after 
the  filings  had  arranged  thein- 
selves.  Such  plots  of  magnetic 
fields  are  quite  familiar  to  most 
of  us.  In  designing  the  magnetic 
circuits  in  apparatus,  it  is  gen- 
erally of  importance  to  lay  them 
out  in  such  a way  that  the 
magnetic  flux  is  uniformly  dis- 
tributed. If  the  lines  are  over- 
crowded in  one  place  it  may 
mean  local  loss  and  heating. 

If  high  voltage  is  placed  be- 
tween two  conductors  there  will 
be  an  attraction  between  them. 

A suspended  piece  of  dielectric, 
as  a glass  fiber,  will  tend  to  turn 
in  definite  directions  at  different 
points  around  the  conducts. 

If  the  conductors  are  brought 


up  through  an  insulating  plane,  as  before,  and 
the  plane  is  dusted  with  a dielectric,  such  as 
mica  filings,  and  tapped,  the  filings  will  fom 
in  arcs  of  circles  beginning  on  one  condimtor 
and  ending  on  the  other  conductor.  Such  an 
experimental  plot  is  shown  in  Fig.  . ® 

dielectric  field  is  thus  made  as  tangible  as  the 
magnetie  field.  Insulation  breaks  down  at 
any  point  when  the  dielectric  flux  density 
at  that  point  exceeds  a given  definite  value. 
In  high-voltage  apparatus  it  is  theretore 


Fig  1.  A Photograph  of  an  Iron-Filing  Map  of  the  Magnetic  Lines  of  Force 
about  Two  Cylinders 


* Fig.  2 was  made  at  10,000  volts.  The 
conductors  were  3 cm.  in  diameter  and  were 
at  a spacing  of  9 cm.  between  centers. 


Fig.  2. 


A Photograph  of  a Mica-Filing  Map  of  the  Dielectric  Lines  of  Force 
between  Two  Cylinders 


THE  ELECTRIC  FIELD 


1187 


important  to  so  design  the  dielectric  circuit 
that  the  flux  density  is  uniform  or  in  propor- 
tion to  the  breakdown  density  of  the  insu- 
lations at  the  different  parts  of  the  circuit. 
In  Fig.  2,  the  density  is  greatest  at  the 
conductor  surface  and  break-down  will  occur 
there  first.  The  dielectric  flux  density  at  any 
point  is  proportional  to  the  volts  per  cm. 
(or  voltage  gradient)  at  that  point.  The 
strength  of  insulation  is  generally  expressed 
in  terms  of  the  voltage  gradient. 

Fig.  3 is  the  superposition  of  Figs.  1 and  2. 
It  represents  graphically  the  magnetic  and 
dielectric  fields  in  the  space  surrounding  two 
conductors  which  are  carrying  energy.  The 
power  is  a function  of  the  product  of  these 
fields  and  the  angle  between  them. 

Fig.  4 is  the  mathematical  or  exact  plot 
corresponding  to  Fig.  3.  In  comparing  Figs. 
3 and  4 only  the  general  direction  and 
relative  density  of  the  fields  at  different 


Fig.  3. 


A Photographic  Superposition  of  Figs.  1 and  2 Representing  the  Magnetic 
and  Dielectric  Fields  in  the  Space  Surrounding  two  Conductors 
which  are  Carrying  Energy 


Fig.  4.  A Mathematical  Plot  of  Fields  shown  in  Fig.  3 


points  can  be  considered.  The  actual  number 
of  lines  in  Fig.  3 have  no  definite  meaning. 
The  dielectric  lines  of  force  in  Fig.  4 are 
drawn  so  that  one  twenty-fourth  of  the  total 
flux  is  included  between  any  two  adjacent 
lines.  Due  to  the  dielectric  field,  points  in 
space  surrounding  the  conductors  have  defi- 
nite potentials.  If  points  of  a given  potential 
are  connected  together,  a cylindrical  surface 
is  formed  about  the  conductor;  this  surface 
is  called  an  equipotential  surface.  Thus, 
in  Fig.  4,  the  circles  represent  equipotential 
surfaces.  As  a matter  of  fact,  the  intersection 
of  an  equipotential  surface  by  a plane  at 
right  angles  to  a conductor  coincides  with  a 
magnetic  line  of  force.  The  circles  of  Fig.  4, 
then,  are  the  plot  of  the  equipotential  sur- 
faces and  also  of  the  magnetic  lines  of  force. 
The  equipotential  surfaces  are  drawn  so  that 
one-twentieth  of  the  voltage  is  between  any 
two  surfaces.  For  example:  If  10,000  volts 
is  placed  between  the  two  con- 
ductors, one  conductor  is  at 
+ 5000  volts,  the  other  at  — 5000 
volts.  The  circle  ( oo  radius)  mid- 
way between  is  at  0.  The  poten- 
tials in  space  on  the  different 
equipotential  surfaces,  starting 
at  the  positive  conductor,  are 
+ 5000,  +4500,  +4000,  +3500, 
+ 3000,  +2500,  +2000,  +1500, 
+ 1000,  +500,  0,  -500,  -1000, 
-1500,  -2000,  -2500,  -3000, 
-3500,  -4000,  -4500  and 

— 5000.  A very  thin  insulated 
metal  cylinder  may  be  placed 
around  an  equipotential  surface 
without  disturbing  the  field.  If 
this  conducting  sheet  is  con- 
nected to  a source  of  potential 
equal  to  the  potential  of  the  sur- 
face which  it  surrounds,  the  field 
is  still  undisturbed.  The  original 
conductor  may  now  be  removed 
without  disturbing  the  outer 
field.. 

The  dielectric  lines  of  force 
and  the  equipotential  sur- 
faces are  at  right  angles  at  the 
points  of  intersection.  The  di- 
electric lines  always  leave  the 
conductor  surfaces  at  right 
angles.  The  equipotential  cir- 
cles have  their  centers  on  the 
line  passing  through  the  con- 
ductor centers;  the  dielectric 
force  circles  have  their  centers 
on  the  neutral  line. 


118S 

The  dielectric  and  magnetic  fields  may  be 
treated  in  a very  similar  way.  For  instance, 
to  establish  a magnetic  field  a mapeto- 
motive  force  is  necessary;  to  establish  a 
dielectric  field  an  electromotive  force  is 
necessary.  If  in  a magnetic  circuit  the  same 
flux  passes  through  varying  cross  sections, 
the  magnetomotive  force  will  not  divide  up 
equally  between  equal  lengths  in  the  circum 
Where  the  lines  are  crowded 
magnetomotive  force  per  unit  length  of  the 
magnetic  circuit  will  be  greater  than  where 
the  lines  are  not  crowded  toother.  i he 
magnetomotive  force  per  unit  length  of  the 
magnetic  circuit  is  called  the  magnetizing 
force.  Likewise,  for  the  dielectric  circuit  where 
the  dielectric  flux  density  is  high  a greater 
part  of  the  electromotive  force  per  unit 
length  of  circuit  is  required  than  at  parts 


GENERAL  ELECTRIC  REVIEW 


where  the  flux  density  is  low.  Electromotive 
force  or  voltage  per  unit  length  of  dielectric 
circuit  is  called  electrifying  force,  or  voltage 
gradient.  If  iron  or  material  of  high  pemiea- 
bility  is  placed  in  a magnetic  circuit  the  flux 
is  increased  for  a given  magnetomotive  force. 
If  there  is  an  air  gap  in  the  circuit  the  magnet- 
izing force  is  much  greater  in  the  air  than  m 
the  iron.  If  a material  of  high  specific  capacity 
or  permittivity,  as  glass,  is  placed  in  the 
dielectric  circuit,  the  dielectric  flux  is  in- 
creased. If  there  is  a gap  of  low  permittivity, 
as  air,  in  the  circuit,  the  voltage  gradient  is 
much  greater  in  the  air  than  in  the  gl^s. 

The  dielectric  circuit  must  always  be  con- 
sidered in  the  proper  design  of  high-voltage 
apparatus.  The  fields 

conductors  may  be  plotted  with  mica  filing 
in  the  same  way. 


SOME  NOTES  ON  BUS  AND  SWITCH  COMPARTMENTS 
FOR  POWER  STATIONS 

By  Emil  Bern 

SW.TCBBOAKD  ENC.NBEK.NC  DEPARTMENT,  GENERAL  EL.CIE.C  COMPANV 

The  bus  and  switch  compartments  of  a study*^  q^s^artmle  incorporates  a description  ; 

system-  and  therefore  their  design  Serves  the  niost  fundamental  rules  ^ 

of  certain  important  advances  that  tiave^^e^ce^tly  fire-proof^bus  and  switch  compartments;  and  it  also  , 

dLJfies™he'dfffSent“^^^^^^^  designs  and  discusses  their  relative  merits.-EDiTOR. 


Large  capacity  power  stations  have  out- 
grown the  switchboard  having  switches  con- 
Lctions  and  buses  supported  on  the  board 
proper  as  the  electrically  operated  switches  of 
large  capacity  are  usually  installed  in  the  posi- 
tion which  is  most  convenient  with  respect  to 
high  potential  buses  and  heavy  connections. 
The  buses  and  all  parts  of  the  switching _sy stern 
must  be  most  carefully  protected  to  avoid  short 
circuits;  and  at  the  same  time  they  should  be 
designed  to  withstand  the  abnormal  conditions 
caused  by  short  circuits  or  overloads,  hor 
heavy  currents  at  medium  high  voltages,  the 
objects  just  named  seem  to  be  best  accom- 
plished by  installing  the  buses,  connections 
and  switches  in  masonry  compartments._ 

The  purpose  of  this  article  is  to  discuss 
briefly  certain  typical  designs  of  fire-proof 
compartments  for  switching  apparatus,  based 
on  the  familiar  type  of  oil  switch  illustrated 
in  Fig.  1 and  Fig.  2.  The  construction  of  the 
two  types  of  switches  is  the  same,  except  or 
the  arrangement  of  the  oil  vessels  and  their 
contacts.  In  both  constructions  the  walls  of 
the  cells  are  built  of  bnck  or  concrete  and 
the  top  and  bottom  of  soapstone  slabs.  W hiie 
not  shown  in  the  illustrations,  there  are 


flame-proof  doors  in  front  of  the  cells.  These  < 
are  hung  from  steel  work  at  the  top  so_  as  to  . 
swing  open  easily  in  case  of  an  explosion  in 

the  cell. 

^'^Concrete  has  gained  in  favor  over  bnck  - 
for  masonry  work  and  therefore  the  mapnty 
of  today’s  bus  and  switch  compartments  are 
built  of  concrete.  In  some  cases  complete  < 
forms  are  made,  usually  of  wood,  and  the  ^ 
whole  compartment  poured.  This  procedure  | 
gives  the  most  substantial  construction,  it 
is  more  often  the  case,  however,  that  concrete 
slabs  are  used  set  in  cement.  When  this 
scheme  of  construction  is  used  the  compart- 
ment is  so  designed  that  w^^^ 
a small  number  of  different  size  slabs.  Fairly 
accurate  work  can  be  obtained  by  this 
method,  and  the  cost  of  forms  is  reduced 

wTere^the  design  of  the  compartment  is 
not  too  complicated,  and  where  the  desired 
dimensions  agree  with  the  size  of  bncks 
available,  brick  construction  is  usually  the 
most  convenient  for  smaller  compartments 
This  is  especially  true  in  cities  where  concre 
work  cannot  be  handled  conveniently  on 


1189 


BUS  AND  SWITCH  COMPARTMENTS  FOR  POWER  STATIONS 


ig.  1.  Bottom-Connected  Oil  Switch.  Parallel  Arranged  Contact; 

■apacities  and  conditions.  From  the  values 
iven  in  the  table  any  bus  compartment  can 


Fig.  2.  Bottom-Connected  Oil  Switch.  Tandem  Arranged  Contacts 

clamps  for  attaching  the  connections  to  the 
buses;  and  also  to  take  into  account  mechan- 
ical clearance  and  convenience  in  installing 
the  material.  The  compartment  shelves  are 
usually  made  about  two  inches  thick;  but 
sometimes  are  thicker  when  made  of  con- 
crete for  large  compartments.  The  thickness 
of  the  barriers  between  phases  is  determined 
by  the  mechanical  strength  of  the  structure; 
this  also  applies  to  the  thickness  of  compart- 
ment walls.  In  brick  compartments  there  is 
very  little  choice,  for  the  dimensions  of  the 
brick  usually  predetermine  them.  In  con- 
crete structures  the  thickness  of  the  walls 
and  barriers  is  generally  from  three  to  four 
inches. 

Disconnecting  Switches 

Several  different  types  of  disconnecting 
switches  are  used.  For  voltages  up  to  3300 
they  are  generally  mounted  on  marble  bases 
without  insulators.  When  provided  with 
insulators  they  are  usually  mounted  on  slate 
or  steel  bases.  The  steel  base  has  the  advan- 
tage of  occupying  small  space,  it  preserves 
the  adjustment  of  the  switch,  and  is  less 
liable  ^ to  injury  during  shipment  and  con- 
struction work.  Fig.  3 shows  several  methods 
of  mounting  disconnecting  switches  in  com- 
partments. 


account  of  lack  of  space.  The  shelves  or 
partitions  are  then  usually  made  of  soapstone 
or  slate,  but  sometimes  of  concrete.  Often- 
times bricks  vary  considerably  in  size,  which 
makes  accurate  work  very  expensive  since 
close  adherence  to  certain  dimensions  often 
' necessitates  cutting  the  bricks  or  making 
abnormal  bonds.  For  this  reason  it  is  usually 
more  satisfactory  to  cut  and  drill  the  buses 
and  connections  when  installing  them  than 
to  make  them  up  beforehand  from  the  com- 
partment drawings. 

The  design  of  fire-proof  bus  compartments 
is  usually  such  as  to  enclose  or  to  separate  the 
i different  phases  of  the  buses  and  connections 
by  masonry.  The  masonry  portions  of  the 
; compartments  must  be  considered  as  being  at 

■ ground  potential;  therefore,  the  general 
dimensions  of  the  compartments  are  deter- 

; mined  primarily  by  the  minimum  allowable 

■ distance  between  live  parts  and  ground  for 
' the  voltages  used.  This  rule  has  already 
I determined  the  most  important  dimensions 

of  bus  supports  and  the  switching  apparatus. 

Fig.  3 shows  sections  of  typical  bus  com- 
partments with  their  fundamental  dimensions 
, for  different  voltages  based  on  average 


easily  be  designed.  It  is,  of  course,  necessary 
to  first  determine  the  dimensions  of  switches, 
busbar  supports,  buses,  connections  and  the 


1190 


GENERAL  ELECTRIC  REVIEW 


Volts 

A 

Ground 

Dist. 

B 

C 

Volts 

A 

Ground 

Dist. 

B 

C 

2.500 

6,600 

15.000 

22.000 
35,000 

2" 

3" 

ZV 

6" 

10" 

9" 

lor 

12" 

20" 

25" 

12" 

14" 

15" 

20" 

25" 

45.000 

70.000 

90.000 
110,000 

14" 

21" 

27" 

33" 

34" 

45" 

56" 

72" 

34" 

45" 

56" 

72" 

to  the  bus,  the  busbars  are  usually  arranged 
horizontally,  i.e.  laid  on  side.  _ 

The  available  space  for  the  switching 
equipment  determines  to  a great  extent  the 
design  of  the  compartments.  Sometimes  the 
buses  are  located  on  the  floor  below  the  oil 
switches,  which  construction  is  very  desirable 
when  using  bottom-connected  switches,  pro- 
vided the  disconnecting  switches  between 
the  oil  switches  and  the  bus  are  located  so 
that  a person  operating  them  can  see  whether 
the  oil  switch  is  open  or  closed.  To  meet 
this  condition,  and  thus  eliminate  the  danger 
of  operating  the  wrong  disconnecting  switch, 
they  may  be  installed  in  a sub-compartment 
in  the  oil-switch  cell  just  above  the  floor.  A 
door  for  this  sub-compartment,  of  the  same 
width  as  the  oil  switch,  helps  to  determine 
without  question  which  disconnecting  switch- 
es belongs  to  a certain  oil  switch. 


Fig.  3. 


Dimensioned  Sectional  Views  of  Typical  Bus 
Compartments  for  Various  Voltages 


Disconnecting  switches  are  occasionally 
used  for  isolating  horizontal  sections  of  the 
bus,  andin  this  case  are  located  in  the  compart- 
ments in  a straight  line  with  the  bus, 
with  the  insulators  secured  either  to  the 
shelf  or  to  the  back  wall  of  the  compart- 
ment. If  the  bus  is  heavy  enough  and 
is  securely  anchored,  it  can  serve  as  the 
hinge  and  clip  for  the  switch,  thus 
simplifying  the  construction  somewhat. 
Whatever  type  of  switch  is  used,  care 
must  be  taken  to  see  that  Pfoper 
clearance  to  ground  is  obtained  with  the 
blade  in  any  position. 

To  withstand,  mechanically,  stresses 
incidental  to  momentary  short  circuit 
and  heavy  overloads,  it  is  necessary  that 
the  buses  and  connections  be  securely 
anchored,  while  at  the  same  time  pro- 
vision must  be  made  for  the  expansion 
and  the  contraction  of  long  buses 
due  to  temperature  changes.  1 he 
bus  supports  may  be  secured  either  to  the 
shelves  or  to  the  back  wall  of  the  compart- 
ment, but  must  be  located  near  openings 
so  as  to  be  accessible  for  cleaning  and  inspec- 
tion. For  convenience  in  joining  connections 


Buses  in  the  Floor 

Fig.  4 shows  a simple  arrangement  of  oil 
switches  with  sub-compartments,  discon- 
necting switches  and  the  buses  installed  in 
the  floor.  The  buses  are  supported  and  are 
accessible  from  below.  Earners  of  asbestos 
lumber  or  similar  matenal  may  be  provided 
between  the  connections  of  different  phases, 
if  considered  necessary.  If  disconnecting 
switches  are  required  on  one  side  of  the  oil 
switch  only,  the  parallel  arranged  oil  switch  ‘ 
may  be  used  and  installed  against  the  wall,  ^ 
as  shown  in  section  A,  Fig.  4.  With  discon- 


Sus 


Section 

Oi/Stvitcn 


L- 

1 ' 1; 

1 ' ■> 

1 1 i| 

!i 

,1 

1 

i' 

I* 

Li 

! ' li  1' 

1 i 'll  <1 

1 

1 

'T'^  ft  iCH  n 
* )Rr|  flUi  Ir  d n 

ro  Generator 
Thonsformer 

Feeder 


D/sconnectinf  Siv/Cch  • 
Gases - 


Fig.  4. 


Two  Arrangements  for  Oil  Switches  wi^  DisconnecUng  Switch 
Sub-Compartments  and  with  Buses  in  the  Floor 


necting  switches  on  both  sides  of  oi 
switch,  it  is  possible  to  arrange  all  of  them  n 
the  sub-compartments  by  providing  spact 
back  of  the  oil  switch  for  operating  them,  o 
by  using  the  tandem  arranged  switch  as  showi 


BUS  AND  SWITCH  COMPARTMENTS  FOR  POWER  STATIONS 


1191 


in  section  B,  Fig.  4.  With  the  first  arrange- 
ment, a bus-section  oil  switch  may  be  installed 
directly  over  the  buses;  while  with  the  tandem 
arranged  switches,  the  construction  can  be 
materially  improved  and  made  more 
compact  by  locating  the  bus-section 
oil  switch  in  line  with  the  other 
switches. 


elements  cannot  be  made  under  the  floor.  A 
very  compact  construction  of  this  kind  is 
shown  in  Fig.  6,  which  provides  for  bus-tie, 
transformer,  and  generator  switches  connected 


Buses  in  Compartments  Below  Oil 

Switch  Floor 

Fig.  5 shows  different  features 
of  a construction  with  bus  com- 
partments on  the  floor  below  the 
oil  switches,  and  with  disconnecting 
switches  arranged  in  sub-com- 
partments. A represents  a bus- 
section  switch;  and  B,  a bus-tie, 
generator,  or  transformer  switch 
connected  according  to  the  dia- 
gram. C shows  the  application  of 
the  tandem  arranged  oil  switch  to 
the  same  conditions  as  A and  B. 
If  the  room  containing  the  bus 
compartments  is  used  for  other 
purposes  also,  it  is  advisable  to 
provide  doors  between  the  barriers 
to  guard  against  accidental  contact 
with  the  connections. 

Bus  and  Switch  Compartments  on 

Same  Floor 


Fig.  5.  Standard  Arrangements  for  OU  Switches  with  Disconnecting  Switch  Sub- 
Compartments  and  with  Bus  Compartments  beneath  the  floor 

It  is  often  necessary  to  install  the 
bus  and  switch  compartments  on  the  same 


floor,  and  in  some  cases  this  floor  is  immedi- 
ately above  the  transformer  compartments,  so 
that  the  connections  between  the  different 


the  same  as  in  Fig.  5.  This  construction 
requires,  however,  a set  of  disconnecting 
switches  arranged  horizontally  in  the  buses. 
Passages  through  the  compartments  can  easily 


B C 


Fig.  6.  Arrangements  wherein  the  Switch  and  Bus  Equipments  are  located  on  the  floor.  Electrically  these 
connections  are  identical  to  those  of  Fig.  5 


1192 


GENERAL  ELECTRIC  REVIEW 


1 

' 

flBSSoge 

Oi/ 

Smtc/) 

Bassege 

— 

: » 

: ~ 9 

\ 

. T 

: 1 

y 

1 

i 1 

1 

1 

nJ:\i 

-i-'- 

_ 4.L 

n 

--4  , 

be  provided  under 
the  main  bus,  as 
indicated  in  the 
Figure. 

Another  construc- 
tion providing  the 
same  electrical  con- 
nections is  shown  in 
Fig.  7.  Here  false 
floors  must  be  pro- 
vided over  the  con- 
nections,  unless 
these  can  be  carried 
through  and  under 
the  floor.  This  false 
floor  over  the  con- 
nections between 
the  oil  switches  and 
the  compartments 
consists  of  remov- 
able slate  slabs 
resting  on  vertical 
brick  or  concrete 
barriers  between  the 
connections.  With 
this  construction  it 
is  necessary  to  pro- 
vide doors  for  the 
compartments  as 
well  as  for  the  oil  switches.  Section  A 
shows  the  construction  of  a bus-tie  con- 
nection, section  B a generator  or  transformer 
connection,  and  the  plan  view  C a com- 
bination of  the  above  for  connecting  a gen- 
erator to  its  transformer  or  to  the  main  bus 
the  same  manner  as  indicated  in  the 


C/rcu/t  Connect ea  to  Main  Bus. 

Fig.  7.  Arrangements  wherein  the  Switch  and  Bus  Equipments 
are  located  on  the  Floor.  A different  but  equivalent 
scheme  to  that  shown  in  Fig.  6 


diagram  of  Fig.  6.  Section  D shows  how  a 
feeder  circuit  may  be  connected  to  the  main 
bus,  and  how  the  instrument  transformers 
may  be  installed  in  line  with  the  auxiliary 
bus  compartment  if  desired.  Disconnecting 
switches  may  also  be  accommodated  in  this 
compartment  for  isolating  the  instrument 
transformers  from  the  line  when  energized 
from  the  other  end. 

A bus-section  oil  switch  with  disconnect- 
ing switches  may  be  installed  as  illustrated  at 
E,  but  it  must,  however,  be  placed  at  right 
angles  to  the  main  compartment. 


PRACTICAL  EXPERIENCE  IN  THE  OPERATION  OF 
ELECTRICAL  MACHINERY 


Part  III  (Nos.  13  to  18  inc.) 
By  E.  C.  Parham 


Construction  Department,  General  Electric  Company 


(13)  TRANSFORMER  LEADS  REVERSED 

Fig.  1 is  a diagrammatic  sketch  of  the 
connections  for  two  direct-current  generators 
connected  to  supply  lights  and  power  by 
three- wire  distribution.  Between  the  middle 
or  neutral  wire  and  either  outside,  the  voltage 
of  one  dynamo  is  available  (110  volts); 
between  the  two  outside  wires,  the  voltage 
available  is  that  of  A and  B in  series  (220 
volts).  Lamps  are  connected  to  adjacent 
wires  and  220-volt  motors  to  the  outside 
wires. 

Wherever  three  wires  are  run,  the  neutral 
should  be  the  middle  one,  because,  as  indi- 
cated in  Fig.  1 (b),  should  the  neutral  and 


uov. 


Fig.  1 


one  of  the  outside  wires  become  accidently 
interchanged  some  of  the  lamps  are  likely  to 
be  blown  up  and  220-volt  motors  connected 
(to  the  outside  wires  will  not  speed  to  their 
rated  r.p.m.  In  Fig.  1 (c)  the  distributing 
wires  are  arranged  correctly  but  the  two 
generators  are  indicated  as  having  been 
connected  so  that  their  voltages  are  in 
opposition  instead  of  in  addition.  In  this 
case  it  is  still  possible  to  get  110  volts  between 


the  middle  wire  and  each  outside  wire,  but 
the  middle  wire  is  no  longer  a neutral  wire; 
it  has  become  the  return  wire  for  the  outside 
wires  and  has  to  carry  the  sum  of  their 
currents  instead  of  the  difference.  Further- 
more, the  voltage  across  the  outside  wires  is 
zero. 


- — HOOV. 

NAAAAAAAAAAAAA/ 


HOOV 

NAAAAAAAAAAMAAA/V 


Fig.  2 


These  sketches  are  suggested  to  explain 
to  an  operator  why  he  might  not  be  able  to 
start  a motor  from  the  outside  lines  of  a 
recently  connected  three-wire  service  when 
supplied  from  a single-phase  transformer, 
even  though  the  lamps  are  operating  normally 
across  both  110-volt  legs. 

Fig.  2 (a)  indicates  the  normal  connections 
of  the  single  primary  and  double  secondary 
of  a single-phase  transformer  when  connected 
for  three-wire  secondary  supply.  It  will  be 
noted  that  the  arbitrarily  selected  current 
directions  are  the  same,  indicating  that  the 
e.m.f.  of  each  secondary  coil  boosts  the  e.m.f. 
of  the  other  secondary  coil  so  that  the  e.m.f. 
of  the  outer  terminals  is  the  sum  of  the 
individual  e.m.f’s,  just  as  in  the  case  of  the 
d-c.  generators  of  Fig.  1 (a).  Fig.  2 (b) 
indicates  the  wrong  connections  to  which 
one  operator’s  trouble  was  due.  One  of  the 
secondary  leads  had  been  interchanged  in 
bringing  it  through  the  bushing.  This 
connection  gave  the  same  conditions  of 
voltage  distribution  as  in  Fig.  1 (c) . 

It  is  important  that  careful  attention  should 
be  given  when  making  connections,  as  in  this 
case,  for  example,  the  error  might  be  dis- 


1194 


GENERAL  ELECTRIC  REVIEW 


covered  only  after  an  attempt  was  made  to 
start  a motor  between  the  outside  wires  or 
after  undue  heating  of  the  middle  (on  account 
of  having  to  carry  the  sum  of  the  outside 
currents  instead  of  the  difference)  was  noted. 

(14)  importance  of  equalizer 

Fig.  3 shows  the  connections  of  two 
generators  of  which  Ai  and  Az  are  armatures, 
Fi  and  F2  are  series  fields,  Ki  and  K2  are 
individual  line  switches,  and  E\  and  Et  are 
equalizer  switches. 

If  Ex  and  F2  are  closed  while  either  machine 
is  carrying  the  load,  part  of  the  current  of  the 
loaded  machine  will  pass  through  the  equalizer 
to  and  through  the  series  field  of  the  idle 
machine,  the  circuit  effect  of  the  equalizer 
being  to  place  the  series  fields  of  the  two 
machines  in  parallel.  The  closing  of  ^^e 
equalizer  switches  adds  to  the  no-load 
excitation  of  the  incoming  machine  and  there- 


by enables  this  machine  to  take  its  share  of 
the  load,  assuming  the  correct  no-load 
adjustments  to  have  been  made.  Within 
certain  limits,  the  equalizer  will  prevent  one 
machine  from  driving  the  other  as  a motor 
in  case  they  should  be  thrown  together  when 
the  voltage  of  the  one  is  considerably  below 
that  of  the  other,  since  the  current  through 
the  equalizer  and  series  field  of  the  low- voltage 
machine  increases  its  excitation.  As  stated, 
there  is  a limit  to  this  automatic  regulation 
because  the  equalizer  possesses  resistance 
and  because  the  excitation  due  to  the  equaliz- 
ing current  is  only  a part  of  the  total  excita- 
tion of  the  machine.  While  the  automatic 
division  of  the  load  upon  the  two  machines 
will  be  impaired  seriously  by  an  unnecessary 
high-resistance  equalizing  connection,  it  is 
improbable  that  such  an  equalizer  would 
cause  sudden  trouble  in  the  operation  of  the 
generators.  If  the  resistance  of  the 
connection,  however,  is  infinite  (caused  by 
the  equalizing  switches  being  open),  it  is  a 
practical  certainty  that  arc-overs  or  other 
like  troubles  will  soon  occur.  Operators, 
therefore,  should  be  sure  that  all  equalizing 


switches  are  closed  between  the  machines 
that  they  are  about  to  parallel. 

(15)  SPARKING  CAUSED  BY  LOAD  CHANGES 
The  series  field  shunts  for  generators  of  low 
and  moderate  current  capacity  are  made  of 
German  silver  ribbon;  those  for  heavy  1 
current  machines  are  made  of  cast-iron  grids. 

In  either  case,  the  shunts  are  constructed 
non-inductively.  The  scheme  of  connections 
employed  is  indicated  in  Fig.  4. 

A shunt  is  arranged  to  have  such  a resist- 
ance that  the  portion  of  the  arrnature 
which  passes  through  the  senes  field  (the 
portion  not  “by-passed”  or  shunted)  will  be 
correct  to  give  the  desired  degree  of  com- 
pounding. The  size  of  the  shunt  which  will  be 
required  is  determined  experirnentally  since 
this  method  of  procedure  is  simple  and  is 

satisfactory  in  most  cases. 

Among  a group  of  motors  which  receives 
its  electric  energy  from  one  generating  source 
there  will  occasionally  be  one  or  more  large 
motors  that  are  frequently  started  and 
stopped,  thereby  causing  sudden  larp  changes 
in  the  output  of  the  generator.  Under  such ; 
conditions  a generator  will  require  a different^ 
type  of  series  field  shunt,  viz.,  an  inductive 
shunt.  If  an  non-inductive  shunt  is  used,  the 
self -inductance  of  the  series _ field  winding, 
will  force  more  than  a proportionate  amount 
of  current  through  the  shunt  during  a peno 
of  sudden  increase  in  load  current,  and,  con-^ 
versely,  it  will  cause  the  series  field  winding^ 
to  retain  more  than  a proportionate  share  | 
of  the  load  current  during  a period  of  sudden? 
decrease  in  load  current.  This  unequal  rate  of  j 
change  of  current  in  the  shunt  and  series  field  : 
winding  will  cause  a distortion  of  the  field  j 
magnetism.  Such  a displacement  of  the  fiux, 
will  probably  result  in  more  or  less  serious; 
sparking  at  the  brushes.  A shunt  which  is- 
non-inductive  will  not  maintain  a constant ^ 
proportional  division  of  the  current  between, 
it  and  the  series  field  winding  (i.e.,  will  not 
maintain  the  series  field  current  proportional 
to  the  load)  during  the  period  of  a rapid 
change  of  load.  Therefore,  the  condition  of 
widelv  varving  load  may  prevent  a non- 
inductive  shunt  from  performing  its  function 
properly. 

When  the  conditions  of  the  load  are 
sufficiently  severe  as  to  make  it  necessary 
to  overcome  this  variable  division  of  the  load 
current  between  the  shunt  and  the  series  field 
winding,  because  of  the  bad  commutation 
produced  thereby,  satisfactory  operation  can 
be  secured  by  including  an  inductive  element 


OPERATION  OF  ELECTRICAL  MACHINERY 


1195 


' in  the  shunt.  This  arrangement  is  indicated 
in  Fig.  5,  in  which  F is  the  series  field,  NS  the 
non-inductive  part  of  the  shunt,  and  IS  the 
inductive  portion.  This  latter  consists  of 
copper  wire  wound  on  an  iron  core  having  an 


y- 


-Shunf  YJ>^er/^s  ^Shunt 
. Qr/etd  ^ rie/d 


flrmalurei 


• Rheostat 


Fig.  4 


air  gap  that  can  be  varied  to  give  the  desired 
amount  of  self-induction.  The  total  ohmic 
resistance  of  the  inductive  and  non-inductive 
I parts  in  series  must  be  such  as  to  give  the 
I required  degree  of  compounding  for  steady 
I currents;  the  resistance  of  the  inductive 
part  must  be  adjusted  by  trial  to  give 
I sparkless  commutation  when  the  load  is 
I suddenly  varied.  Since  the  inductive  part 
I necessarily  has  some  ohmic  resistance,  a 
t change  of  taps  in  this  part  in  order  to  change 
its  self  induction  will  also  change  its  ohmic 
resistance  and  hence  the  total  ohmic  resistance 
of  the  shunt.  Frequently,  the  whole  inductive 
change  can  be  made  by  means  of  the  air-gap, 
which,  of  course,  will  not  change  the  ohmic 
resistance.  Final  adjustment  will  require  a 
trial  of  several  combinations  of  inductive 
and  non-inductive  shunt. 

As  a practical  illustration  of  the  operation 
of  shunts,  reference  may  be  made  to  an 
instance  where  momentary  sparking  of  gener- 


ators and  their  tendency  to  flash  over  was 
caused  by  the  starting  and  the  stopping  of 
heavy  direct-current  motors  in  a cement  mill. 
An  inductive  shunt  was  later  obtained  and 
connected  in  series  with  the  non-inductive 
shunt,  and  then  the  resistance  of  the  latter 
was  decreased  until  the  combined  resistance 


of  the  two  elements,  inductive  and  non- 
inductive,  was  the  same  as  the  resistance 
of  the  original  non-inductive  shunt  alone. 
In  this  particular  case  it  was  unnecessary 
to  make  any  adjustments  of  self-induction 
in  the  inductive  shunt  because  by  coincidence 
the  amount  happened  to  be  correct. 

(16)  REVERSED  FIELD  COILS 

If  one  or  more  field  coils  are  reversed  on  a 
generator  of  any  type,  one  result  is  to  lower 
the  voltage  obtainable  from  the  armature. 
In  the  case  of  a direct  current  generator, 
sparking  at  the  commutator  will  also  suggest 
the  possibility  of  reversed  field  coils;  in  the 
case  of  an  alternator,  however,  as  there  is  no 
commutator,  the  sparking  symptom  will  be 
absent.  In  any  case,  the  magnitude  of  the 
effect  will  depend  somewhat  on  the  relation 
between  the  number  of  reversed  poles  and 
the  total  number  of  poles  in  the  machine. 

A large  alternator,  which  was  excited  from 
a multi-polar  generator,  was  packed  so  full 
of  mud  and  wood  as  the  result  of  being 
submerged  during  a flood  that  it  had  to  be 
dismantled  for  cleaning.  The  exciter  also  had 
been  through  the  same  experience.  After 
reassembling,  it  was  impossible  to  generate 
normal  voltage.  Everyone  attributed  the 
trouble  to  dampness  and  the  two  machines 
were  baked  “almost  to  death ” in  a determined 
effort  to  dry  them.  Finally,  it  was  noticed 
that  both  machines  were  about  dry  and  that 
further  drying  was  not  improving  the  condi- 
tions materially.  Further,  it  was  observed 
that  there  was  more  sparking  at  the  exciter 
commutator  than  formerly.  An  investigation 
disclosed  a field  spool  of  reversed  polarity. 
This  error  of  assembly  was  corrected  and  it 
was  supposed  that  all  trouble  had  been 
eliminated.  On  starting,  however,  it  was 
found  to  be  impossible  to  get  the  alternator 
voltage  much  higher  than  it  was  before. 
(The  effect  upon  the  exciter  voltage  could 
not  be  observed  because  there  was  no  direct 
current  voltmeter  available.)  Then  it  was 
suggested  that  some  of  the  poles  of  the 
alternator  might  be  reversed,  as  in  the  case 
of  the  exciter.  This  proved  to  be  the  case: 
Out  of  a total  of  32  poles,  five  poles  of  reversed 
polarity  were  found  distributed  around  the 
revolving  field.  The  correcting  of  this  fault 
enabled  normal  voltage  condition  to  be 
restored. 

(17)  RIDGING  OF  COMMUTATOR 

By  ridges  on  a commutator  are  meant  those 
alternate  high  surfaces  which  remain  when 


119G 


GENERAL  ELECTRIC  REVIEW 


intervening  grooves  are  cut  in  the  commu- 
tator by  the  brushes.  This  may  be  due  to 
sparking  (visible  or  invisible) , to  lack  of 
end-play  in  the  armature,  to  tracking  of  the 
brushes  (that  is,  placing  the  brushes  along 
circumferential  lines  on  the  commutator  so 
that  certain  zones  of  the  surface  are  not 
subjected  to  brush  wear),  or  to  excessive 
brush  tension.  Sparking  which  may  be  so 
slight  that  it  cannot  be  seen  in  a well-lighted 
room  becomes  evident  in  a dark  roorn. 
kind  of  sparking  may  be  due  to  using  the 
wrong  quality  of  brush.  Even  with  staggered 
brushes  end-play  is  essential  to  good  perma- 
nent commutator  operation.  The  movement 
can  generally  be  obtained  by  insuring  that 
the  machine  is  actually^  level,  but  if 
amount  of  play  is  insufficient  it  should  be 
secured  in  some  way  even  if  it  is  necessary  to 
turn  off  the  inside  end  of  one  of  the  armature 
bearings.  The  brush  tension  should  be  no 
greater  than  is  required,  the  proper  amount 
being  obtained  by  trial  and  observation. 
When  the  brushes  are  not  properly  staggered, 
even  if  the  commutation  is  of  the  best,  the 
unwiped  part  of  the  commutator  in  course  of 
time  will  stand  above  the  wiped  part,  unless 
this  tendency  is  overcome  by  well-applied 
sanding  of  the  ridges.  If  both  lubricating 
and  standard  brushes  are  used  on  a machine, 
they  should  be  distributed  as  far  as  possible 
so  that  each  kind  is  correctly  staggered  in 
regard  to  that  and  the  other  kind. 

Notwithstanding  the  fact  that  all  ordinary 
precaution  had  been  taken,  the  skilled 
operators  of  a certain  station  seeming  y 
found  that  a ridge  on  one  commutator  cou  d 
not  be  prevented.  It  was  finally  noticed  that 
all  the  positive  brushes  were  staggered  with 
regard  to  each  other,  as  were  also  the 
tives ; the  positive  tracked  positive,  and  the 
negative  tracked  negative,  and  the  positives 
were  cutting  grooves.  On  re-arranging  the 
brushes  correctly  on  the  holders  all  grooving 
and  ridging  stopped. 

LAMPS  FLICKERING 

The  full  lines  of  the  diagram  in  Fig.  6, 
represent  the  connections  of  a two-poffi, 
direct-current  armature  mounted  upon  the 


same  shaft  with  a circular,  iron-cored  react-  , 
ance,  the  two  members  constituting  the  mam  i 
feature  of  a so-called  three-wire  generator. 
The  end  connections  of  the  reactance  are 
tapped  to  diametrically  opposite  points  of 
the  armature  winding  and  it  is  very  essential 
that  these  points  be  diametrically  opposite. 
From  the  center  of  the  reactance  is  run  a wire 
called  the  neutral;  this  neutral,  in  conjunction 
with  the  two  outside  wires  from  the  generator, 
constitutes  the  three-wire  distributing  line. 
The  reactance  is  simply  a device  by  rneans 
of  which  the  internal  neutral,  or  half -voltage 
point  of  the  armature,  may  be  reached. 
Half  of  the  series  field  winding  of  the  gener- 
ator is  placed  in  one  main,  or  outside 
and  the  remaining  half  in  the  other  to  help 
balance  the  voltage  when  the  load  becomes  j 

unbalanced.  . , ; 

With  balanced  load,  the  current  in  each  ^ 
main  is  the  same  and  the  current  in  the  , 
neutral  is  zero.  The  turning  off  of  lamps  on 
one  side  and  not  on  the  other  tends  to  raise 
the  voltage  of  the  more  lightly  loaded  side;  ■ 
this  tendency  is  partly  neutralized  by  the 
weakened  series  field  on  that  side  acting  to 
lower  the  voltage.  The  reactance  carries  ' 
alternating  exciting  current  all  the  time,  and 
it  carries  direct  current  only  when  the  load  ; 
is  unbalanced.  In  this  latter  case  there  is  a : 


neutral  current  and  it  is  equal  to  the  difference  ' 
between  the  current  in  the  two  mains. 

A case  of  severe  flickering  of  the  lamps 
furnished  with  energy  by  a certain  three-wire 
generator  was  traced  to  the  tap  of  the 
neutral  wire  on  the  reactance  coil 
center,  as  shown  by  the  dotted  line  in  Fig.  b. 


1197 


RECENT  VIEWS  ON  MATTER  AND  ENERGY 


Part  IV 


By  Dr.  Saul  Dushman 


Research  Laboratory,  General  Electric  Company 

In  this  issue,  the  last  of  the  series,  the  author  indicates  the  manner  in  which  the  atomic  theory  of  mat- 
ter has  been  affected,  by  the  atomistic  theories  of  electricity  and  energy.  The  result  of  all  the  recent  investi- 
gations and  speculations  has  been  to  strengthen  more  firmly  the  position  held  by  the  older  theory  of  the 
atomic  and  molecular  structure  of  matter.  The  greatest  interest  now  centers  in  the  question  as  to  the 
structure  of  the  atom  itself,  and  in  this  connection  the  views  of  Rutherford  and  Bohr  seem  to  be  in  best 
accord  with  actual  observations. 


ATOMIC  THEORY  OF  MATTER 


It  is  evident  from  what  has  been  stated 
so  far  that  the  tendency  of  modem  physics 
is  to  adopt  atomistic  views  in  the  explanation 
of  all  phenomena.  We  have  an  atomic  theory 
of  electricity,  an  atomic  theory  of  energy 
and  we  have  been  familiar  for  over  a century 
with  an  atomic  theory  of  matter. 

The  theory  in  which  Dalton  found  such 
a simple  explanation  of  the  fundamental  laws 
of  chemical  combination  has,  as  is  well 
known,  been  regarded  as  unnecessary  by  one 
school  of  chemists,  while  a number  of  others 
have  adopted  the  faith  of  their  colleagues, 
the  physicists,  and  prefer  to  speak  of  atoms 
and  molecules  rather  than  of  international 
and  reacting  weights. 

It  is  not  our  intention  in  this  paper  to 
enter  into  any  polemical  arguments  as  to 
which  attitude  is  the  more  correct.  We  are 
here  concerned  mainly  with  a recital  of 
experimental  facts  and  a presentation  of  the 
theories  which  have  been  put  forward  in 
explanation. 

Applications  of  Kinetic  Theory  of  Gases 

The  first  great  impetus  to  the  adoption  of 
the  atomic  and  molecular  theories  of  the 
structure  of  matter  was  undoubtedly  given 
by  the  speculations  of  Maxwell,  Boltzmann 
and  Clausius.  The  kinetic  theory  of  gases 
indicated  simple  relations  between  the  vis- 
cosity, heat  conductivity  and  diffusion  coeffi- 
cients of  gases;  the  validity  of  these  relations 
has  been  confirmed  experimentally. 

Similar  considerations  were  extended  to  the 
case  of  solids  and  liquids,  and  we  have 
observed  that  in  this  manner  Boltzmann 
was  able  to  calculate  atomic  heats  and  to 
account  for  the  law  of  Dulong  and  Petit. 
More  recently,  the  study  of  the  motions  of 
ultra-microscopic  particles,  such  as  are 


present  in  colloidal  solutions  has  led  to 
results  that  are  in  splendid  accord  with  the 
deductions  from  the  kinetic  theory  of  gases. 
The  number  of  molecules  per  gram-mol  of 
any  substance  has  been  determined  in  half  a 
dozen  different  ways,  and  it  is  quite  justifiable 
to  state  that  “today  we  are  counting  the 
number  of  atoms  in  a given  mass  of  matter 
with  as  much  certainty  and  precision  as  we 
can  attain  in  counting  the  inhabitants  in  a 
city.  No  census  is  correct  to  more  tjian  one 
or  two  parts  in  a thousand,’’  and  there  is 
little  probability  that  the  number  of  mole- 
cules in  a cubic  centimeter  of  a gas  under 
standard  conditions  differs  by  more  than 
that  amount  from  27.09 XIO^^* 

Observations  in  Support  of  Atomic  and  Molecular 
Theories 

The  study  of  radio-active  phenomena  has 
given  powerful  support  to  these  atomic  and 
kinetic  conceptions;  we  see  the  disintegration 
of  atoms  going  on  under  our  own  eyes,  as  it 
were.  The  spinthariscope  is  tangible  evidence 
of  atoms  in  motions,  and  very  recently 
C.  T.  R.  WilsoM  has  succeeded  in  photo- 
graphing the  tracks  of  alpha  and  beta 
particles  as  they  shoot  out  spontaneously 
with  immense  velocities. ^ 

The  investigations  of  J.  J.  Thomson  on 
positive  ions  which  ought  to  be  mentioned 
in  this  connection,  have  enabled  us  to 
measure,  independently  of  other  methods, 
the  masses  of  the  positively  charged  molecules 
that  are  repelled  from  the  anode  of  an  ordi- 
nary X-ray  discharge  tube.  The  method  used 
is  practically  the  same  as  that  used  for  the 

REviEw^i^lgralit”"'’ 

'Proc.  Roy.  Soc.  87,  277  (1912). 

2See  pl^tographs  of  the  tracks  of  alpha  particles  in  General 
Electric  Review,  July  1913 


1198 


GENERAL  ELECTRIC  REVIEW 


determination  of  ejm  for  the  cathode  rays.® 
Not  only  has  J.  J.  Thomson  determined  in 
this  manner  the  nature  of  the  different 
constituents  of  a gas  mixture,  but  he  has  also 
shown  that  this  method  of  chemical  analysis 
is  infinitely  more  refined  than  any  other 
method  hitherto  used. 

Similarly  S.  C.  Lind^  has  shown  that  in  the 
case  of  chemical  reactions  produced  by  alpha 
particles,  the  weight  of  evidence  is  in  favor 
of  the  theory  that  each  alpha  particle  pro- 
duces one  ion  by  bombardment  of  molecules 
and  that  subsequently  these  ions  react  to 
form  neutral  molecules. 


Arrangement  of  Atoms  in  Crystals 

Experimental  evidence  of  the  atomic  struc- 
ture of  matter  has  been  obtained  recently  by 
still  another  method.  It  has  already  been 
mentioned  that  considerations  based  on  the 
quantum  theory  led  to  the  conclusion  that 
X-rays  are  merely  electromagnetic  waves  of 
extremely  short  wave-length  (10“®  to 
cm).  To  measure  these  wave-lengths  in  the 
usual  manner  by  means  of  a ruled  diffraction 
grating  was  therefore  out  of  question.  It 
occurred  to  Laue  that  in  the  regular  arrange- 
ments of  atoms  in  a crystal  we  have  gratings 
whose  lines  are  naturally  “ruled”  so  closely 
that  their  distances  are  of  the  same  order  of 
magnitude  as  the  wave-lengths  of  X-rays. 
On  passing  the  X-rays  though  a crystal 
diffraction  patterns  were  obtained,  and  from 
the  photographs  of  these  it  was  found  that 
the  observed  wave-lengths  were  of  the  same 
magnitude  as  those  calculated. 

But  within  the  past  year  still  more  interest- 
ing results  have  been  obtained  by  Bragg  and 
Bragg,®  who  have  used  this  method  to 
determine  the  structure  of  crystals.  We  can 
now  see,  as  it  were,  the  manner  in  which  the 
atoms  in  a crystal  of  rock  salt  or  zinc  blende 
are  arranged,  and  we  can  even  tell  whether 
these  atoms  are  at  rest  or  vibrating  about 
some  position  of  equilibrium.  Thus,  we  find 
that  in  a crystal  of  NaCl,  the  sodium  and 
chlorine  atoms  are  arranged  in  the  form  of  a 
cubical  lattice-work  with  chlorine  and  sodium 
atoms  situated  in  alternate  corners,  so  that 
for  example  ' " the  sodium  atom  has  six 
neighboring  chlorine  atoms  equally  close 


3The  beam  of  positive  rays  is  passed  through  magnetic 
and  electrostatic  fields  acting  at  right  angles  to  each  other  and 
to  the  path  of  the  rays.  From  the  photograph  obtained  when 
the  deflected  beam  strikes  a sensitive  plate,  it  is  possible  to 
calculate  e/m;  consequently,  if  there  is  more  than  one  kind  ot 
ion,  its  presence  is  revealed  by  a separate  streak  on  the  plate. 
See  Proc.  Roy.  Soc.  89,  pp..l-20,  1913,  for  full  details,  also  a 
recent  monograph  on  "Positive  Ions  by  J.  J.  Thomson. 


^Trans.  Am.  Electrochem.  Soc.  24.  339  (1913). 


with  which  it  might  pair  off  to  form  a molecule 
of  Nad”  In  the  case  of  the  diamond  the 
results  obtained  are  equally  striking.  Every 
carbon  atom  is  found  to  be  united  to  four 
neighbors  in  a perfectly  symmetrical  way, 
while  six  carbon  atoms  are  linked  into  a ring 
similar  to  that  used  to  represent  the  benzene 
molecule.  These  results  are  among  the  most 
interesting  that  have  been  obtained  in  recent 
years.® 

In  view  of  these  observations,  the  stereo- 
chemical models  of  the  organic  chemist  are 
endowed  with  an  even  greater  degree  of 
approximate  reality  than  was  hitherto 

dreamed  of.  _ . 

We  are  getting  a glimpse,  as  it  were,  into 
the  innermost  structure  of  the  molecules,  and 
are  learning  daily  more  and  more  about  the 
manner  in  which  their  constituent  atoms  are 
bound  together. 


Structure  of  the  Atom.  Theories  of  J.  J.  Thomson 

and  Stark 

But  not  only  do  we  know  something  about 
the  structure  of  the  molecule,  we  are  also  in  a 
fair  way  to  knowing  something  about  the 
structure  of  the  atom,  the  unit  out  of  which 
molecules  are  built  up.  We  have  learned 
already  that  the  atoms  must  contain  elec- 
trons. The  obvious  conclusion  is  that  besides 
electrons  the  atom  contains  also  a positively 
charged  residue  or  nucleus.  In  what  manner 
are  these  electrons  and  nucleus  related  to  each 
other,  and  to  the  properties  of  the  resulting 
atom?  Here  we  touch  upon  the  most  funda- 
mental problem  of  physics  as  well  as  chemis- 
try. 

Of  the  many  attempts  that  have  been  made 
in  recent  years  to  formulate  a theory  as  to  the 
structure  of  the  atom,  those  of  J.  J.  Thomson 
and  of  Stark  are  among  the  most  important. 
Here  we  can  only  mention  these  theories 
very  briefly.^ 

According  to  Thomson  the  atom  consists  of 
a positively  charged  outer  sphere  with  the 
electrons  arranged  uniformly  on  one  or  more 
spherical  shells  inside.  By  means  of  this 
theory  it  is  possible  to  account  for  the  fact 
that  the  properties  of  the  elements  are  periodic 
functions  of  the  atomic  weight;  also,  for  the 
existence  of  certain  valency  relations. 

Stark’s  theory  lays  most  emphasis  on  the 
existence  of  so-called  valency  electrons.  He 


^W.  L.  Bragg,  Proc.  Roy.  Soc.  89,  248—277  (1913). 

W.  H-  Bragg,  Proc.  Roy.  Soc.  89,  277—291  (1913). 

®See  also  still  more  recent  papers  by  W.  L.  Bragg  and  W.  H. 
Bragg  in  Proc.  Roy.  Soc. 

7An  excellent  discussion  is  given  in  Campbell's  Modern 
Theory,  second  edition.  Chapter  XIII. 


RECENT  VIEWS  ON  MATTER  AND  ENERGY 


1199 


imagines  that  a chemical  combination  between 
i;  two  atoms  “represents  not  a direct  attraction 
' of  one  atom  for  the  other,  but  a simultaneous 
attraction  of  both  atoms  for  the  same  electron 
' which  thus  forms  a bond  between  the  atoms.” 

, On  this  theory,  “the  energy  of  chemical 
. combination  represents  the  change  in  the 
; potential  energy  of  the  valency  electrons 
connecting  the  atoms  which  takes  place  when 
they  transfer  some  of  their  lines  of  force  from 
the  electro-positive  to  the  electro-negative 
atom.  It  will  be  the  greater  the  less  the 
attraction  of  the  former  atom  for  an  electron, 
and  the  greater  the  attraction  of  the  latter.” 
By  far  the  most  important  contribution 
i that  has  yet  been  made  to  this  subject  is, 
however,  contained  in  a series  of  papers  by 

i N.  Bohr*  that  appeared  during  the  latter 
half  of  the  past  year. 

Interpenetration  of  Atoms 

To  understand  the  arguments  advanced 

ii  by  this  writer,  it  is  necessary  to  refer  to  a 
number  of  experiments  that  were  carried  out 
in  Rutherford’s  laboratory  and  which  led  him 

; to  a new  conception  of  the  structure  of  the 
; atom. 

Rutherford  and  Geiger  found  that  when 
the_  alpha  particles  from  radium  or  other 
radio-active  substance  met  a thin  gold  leaf, 
most  of  these  passed  though  the  metal  with 
only  slight  deflection,  but  now  and  then  one 
of  these  particles  was  completely  deflected 
around  so  that  it  returned  towards  the  side 
of  the  source.  This  phenomenon,  known  as 
the  scattering  of  alpha  particles,  was  found 
to  obey  the  same  laws  as  the  repulsion  of  one 
electric  charge  in  motion  by  another  charge 
of  similar  sign  at  rest. 

The  moving  alpha  particle  carries  a positive 
charge  which  is  twice  as  great  as  that  of  the 
electron.  It  is  in  fact  the  same  as  the  helium 
atom  with  two  positive  charges. 

From  the  amount  of  scattering  suffered 
by  some  of  these  particles,  the  conclusion 
was  drawn  that  at  some  point  in  their  paths 
these  particles  pass  through  the  very  intense 
electrostatic  field  caused  by  a positive  charge 
whose  magnitude _ is  approximately  equal  to 
one-half  the  atomic  weight  of  the  metal  through 
which  the  scattering  occurs.  Furthermore,  the 
conclusion  was  drawn  that  the  alpha  particle 
must  approach  the  repelling  positive  charge 
(or  nucleus)  within  a distance  which  is  infin- 
itesimal as  compared  with  the  radius  of  the 
atom.  While  the  radius  of  an  atom  is  about 

*Phil.  Mag.  26,  1-25;  476-502;  857-875  (1913). 


cm.,  the  experiments  on  the  scattering 
of  alpha  particles  by  hydrogen  showed  that 
the  former  must  have  approached  the  hydro- 
gen nucleus  so  closely  that  their  centers  were 
only  1.7X10-1*  cm.  apart.  In  other  words, 
it  was  necessary  to 'conclude  that  the  alpha 
particle  penetrated  within  the  atom  of  the  other 
metal. 

Rutherford’s  Atom  Model 

These  results  led  Rutherford  to  assume  a 
structure  of  the  atom  which  is  quite  different 
from  that  of  J.  J.  Thomson.  According  to  the 
former  “the  atom  must  be  assumed  to  consist 
of  a positively  charged  nucleus  surrounded 
by  a system  of  electrons  which  are  kept 
together  by  attractive  forces  from  the 
nucleus.  This  nucleus  is  assumed  to  be  the 
seat  of  the  essential  part  of  the  mass  of  the 
atom,  and  to  have  linear  dimensions  exceedingly 
small  compared  with  the  linear  dimensions 
of  the  whole  atom."  Furthermore,  as  the 
magnitude  of  the  positive  charge  in  this 
nucleus  corresponds  to  half  the  atomic 
weight,  it  is  necessary  to  assume  that  the 
number  of  electrons  rotating  about,  the 
nucleus  is  equal  to  one-half  the  atomic  weight. 

The  difference  between  the  atom  models 
of  Rutherford  and  Thomson  may  be  illus- 
trated by  means  of  the  diagrams  shown  in 

Fig.  1. 


+ 


Fig.  1 

In  this  connection  it  is  worth  noting  that 
as  a result  of  experiments  on  the  scattering 
of  X-rays,  Barkla  was  led  some  years  earlier 
to  conclude  that  the  number  of  electrons  in 
the  atom  _ must  be  equal  to  one-half  the 
atomic  weight. 

Bohr’s  Theory  of  the  Structure  of  Atoms  and  Mole- 
cules 

While  the  experimental  results  thus  pointed 
towards  a nuclear  structure  of  the  atom,  it 
was  found  that  there  are  apparently  good 
theoretical  reasons  for  assuming  that  such 
an  atom  would  be  quite  unstable.  According 
to  the  classical  electro-dynamics  an  electron 
rotating  about  a positive  charge  would  very 
quickly  radiate  its  energy  in  the  form  of 


1200 


GENERAL  ELECTRIC  REVIEW 


electromagnetic  waves,  its  orbit  would  grow 
smaller  and  smaller,  with  increasing  speed, 
until  finally  the  electron  struck  the  positive 
nucleus.  No  such  objections  could,  however, 
be  raised  against  the  model  of  Thomson. 

But  according  to  Bohr  the  difficulties  in 
the  way  of  assuming  Rutherford’s  atom 
model  disappear  when  account  is  taken  of 
the  fact  that  the  classical  electro-dynamics 
has  been  found  inadequate  in  describing 
the  behavior  of  systems  of  atomic  size.  “By 
the  introduction  of  Planck’s  constant  h,  the 
question  of  the  stable  configurations  of  the 
electrons  in  the  atoms  is  essentially  changed, 
and  it  is  on  the  basis  of  Planck’s  theory  of 
energy  that  Bohr  builds  up  a theory  of  the 
structure  of  atoms  and  molecules. 

The  principal  assumptions  made  by  him 
are  as  follows ; 

(1)  That  the  electrons  revolve  in  circular 
orbits  about  the  positive  nucleus,  with  an 
angular  momentum  which  is  the  same  for  all 
the  eleetrons  in  the  atom.  That  is,  for  each 
electron,  mvr  = hj2  tt,  where  m denotes  the 
mass,  V the  velocity,  and  r the  radius;  or 
the  angular  momentum  is  equal  to  Planck’s 
constant  divided  by  2 tt. 

(2)  That  in  the  stationary  state  the 
dynamical  equilibrium  of  such  a systern  can 
be  discussed  by  the  help  of  the  ordinary 
mechanics.  In  other  words,  the  relation 
between  the  frequency  of  rotation  {v),  the 
average  kinetic  energy  of  the  electron,  and 
the  radius  of  the  orbit  (r)  can_  be  calculated 
by  the  laws  of  ordinary  dynamics. 

(3)  That  in  the  stationary  orbit  no  energy 
is  radiated.  This  is  contrary  to  the  classical 
electro-dynamics.  When,  however,  in  conse- 
quence of  emission  or  absorption  of  energy, 
the  frequency  changes,  the  problem  is  no 
longer  one  that  can  be  dealt  with  by  ordinary 
dynamics.  During  the  latter  process  there  is 
an  emission  or  absorption  of  a homogeneous 
radiation,  whose  frequency  (v)  is  the  average 
of  the  frequencies  of  rotation  before  and 
after  the  energy  change.  The  amount  of 
energy  radiated  or  absorbed  is  then  equal  to 
some  integral  multiple  oih  v. 

From  these  assumptions  Bohr  deduces  a 
number  of  interesting  results.  Assuming,  as 
known,  the  values  of  the  elementary  charge  e, 
the  mass  of  the  electron  m,  and  Planck  s 
constant  h,  he  calculates  the  radius  of  the 
electronic  orbit  to  be  equal  to  that  of  the 
atom  and  the  frequency  of  the  energy  radiat- 
ed to  be  about  the  same  magnitude  as  the 
frequency  of  ordinary  visible  radiation. 


Furthermore,  he  calculates  the  ionization 
voltage,  that  is,  the  work  required  to  expel  an 
electron  from  an  atom,  and  obtains  a result 
that  is  in  agreement  with  observed  values. 

Bohr  also  shows  that  his  theory  enables 
him  to  account  for  the  well-known  laws  of 
B aimer  and  Rydberg  connecting  the  fre- 
quencies of  the  lines  in  the  line-spectra  of 
the  ordinary  elements.  He  finds 


V - 


2 7T^  me^^  /I 1_\ 


where  a and  b are  integers  and  the  other 
letters  have  the  usual  significance.  The 
quantity  before  the  bracket  should  be  equal 
to  the  Rydberg  constant  of  which  the  observed 
value  is  3.29Xl0ih  Bohr’s  calculated  value 
is  3.26X10^h 


Nuclear  Charge.  Atomic  Number 

On  the  basis  of  the  above  assumptions, 
Bohr  also  shows  that  the  configuration  of  any 
system  of  electrons,  i.e.,  the  frequency  and 
linear  dimensions  of  the  rings,  is  completely 
determined  when  the  nuclear  charge  and  the 
number  of  electrons  in  the  different  rings  are 
given.  Corresponding,  however,  to  different  ^ 
distributions  of  electrons  in  the  rings,  there 
will,  in  general,  be  more  than  one  configura-  ‘ 
tion  satisfying  the  conditions  of  angular  j 
momentum  and  stability.  The  physical  and  i 
chemical  properties  thus  depend  upon  the  ^ 
munber  of  electrons,  or  nuclear  charge,  and  the  ^ 
mode  of  arrangement  of  these  electrons.  , 
The  experimental  evidence  supports  the 
hypothesis  that  the  nuclear  charge  of  _ the 
atom  of  any  element  corresponds  to  the  position  • 
of  the  element  in  the  series  of  increasing  atomic  j 
weights.  Thus,  the  oxygen  atom  being  eighth  | 
in  the  series,  should  have  a nuclear  charge  j 
of  eight  unit  charges  and  eight  electrons.  \ 
The  periodic  table  of  the  elements  thus  | 
assumes  a new  significance.  The  order  of  the  j 
elements  in  this  table  corresponds  to  the 
number  of  unit  positive  eharges  of  the  nucleus. 
According  to  Bohr’s  theory,  the  physical  and 
chemical  properties  of  the  atom  depend  upon 
the  magnitude  of  this  nuclear  number;  since, 
however,  any  given  number  of  electrons  may 
often  assume  different  configurations  it  is 
possible  for  two  or  more  elements  to  exist 
having  the  same  nuclear  charge,  that  is, 
the  same  place  in  the  periodic  table,  but  possess- 
ing different  atomic  weights. 

This  is  quite  in  accord  with  the  conclusions 
reached  by  Soddy  and  Fajans  independently, 
from  a consideration  of  the  transformations 
that  occur  in  the  radio-active  elements.  The 


RECENT  VIEWS  ON  MATTER  AND  ENERGY 


1201 


discussion  of  these  deductions  is,  however, 
reserved  for  a subsequent  paragraph. 

Again,  according  to  Bohr’s  theory  the 
emission  of  characteristic  X-rays  is  accounted 
for  as  being  due  to  the  removal  of  an  electron 
from  an  inner  ring.  On  the  other  hand,  the 
radio-active  changes  depend  upon  trans- 
formations occurring  within  the  nucleus  itself. 
The  formation  of  a helium  atom  from  an 
alpha  particle  is  a case  of  the  actual  formation 
of  an  atom  from  a positive  nucleus  and  two 
electrons. 

Bohr’s  Theory  of  the  Method  of  Formation  of  a 
Hydrogen  Molecule 

Bohr  gives  a very  interesting  picture  of 
the  manner  in  which  two  hydrogen  atoms 
form  a molecule.  The  hydrogen  atom  has 
the  simplest  imaginable  structure;  it  consists 
of  a nucleus  of  unit  positive  charge  and  one 
electron  revolving  round  it.  “The  nuclei  of 
two  such  atoms  repel  each  other.  The  revolv- 
ing electrons  of  two  atoms  close  together, 
if  rotating  in  the  same  direction,  constitute 
two  parallel  currents  of  electricity,  and  these 
attract  one  another  and  arrive  in  the  same 
plane.’’  The  molecule  thus  consists  of  the 
electrons  that  revolve  like  the  governor-balls 
of  an  engine  about  an  axis  formed  by  the  two 
nuclei.  Bohr  calculates  the  energy  that 
would  be  liberated  in  the  process  of  combina- 
tion of  the  atoms  and  obtains  a result  in 
substantial  agreement  with  the  value  pre- 
viously calculated  by  I.  Langmuir.® 

If  the  value  of  a theory  is  to  be  measured 
by  the  number  of  observations  it  correlates 
and  by  its  suggestiveness  then  Bohr’s  theory 
of  the  structure  of  atoms  and  molecules  is 
one  of  the  most  important  contributions  to 
scientific  literature  that  has  been  made  in 
recent  years. 

Other  Theories  of  Atomic  Structure 

J.  J.  Thomson^®  and,  more  recently, 
Peddie“  have  suggested  other  atom  models. 
According  to  the  former,  the  intra-atomic 
forces  need  not  necessarily  obey  the  observed 
electrostatic  laws,  and  he  assumes  that  the 
forces  acting  upon  an  electron  in  the  atom  are, 
firstly,  a radial  repulsive  force,  varying 
inversely  as  the  cube  of  the  distance  from  the 
center  and  diffused  uniformly  throughout 
the  whole  of  the  atom,  and  secondly,  a radial 
attractive  force,  varying  inversely  as  the 

9J.  Amer.  Chem.  Soc.  SJf,  860  (1912),  also  Phil.  Mag., 
Jan.,  1914. 

‘“Phil.  Mag.  26,  792-799,  (1913). 

“Phil.  Mag.  27,  257-268,  (1914). 


square  of  the  distance  from  the  center  and 
confined  to  a limited  number  of  radial  tubes 
in  the  atom.  On  the  basis  of  this  theory 
Thomson  is  able  to  account  for  the  relation 
between  velocity  of  emission  of  electrons  and 
frequency  of  incident  radiation  as  demanded 
by  the  quantum  theory;  and  he  is  also  able 
to  account  for  Balmer’s  law. 

Professor  Peddie  would  also  explain  the 
variation  in  properties  of  atoms  and  molecules 
in  a similar  manner  as  due  to  structural 
conditions  within  the  atom  rather  than  to  the 
failure  of  the  ordinary  dynamical  equations 
in  the  case  of  such  systems,  and  along  with 
Thomson  he  postulates  regions  of  attractive 
force  alternating  with  regions  of  repulsive 
force. 

Bohr’s  theory  has,  however,  proven  so  far 
to  be  the  most  stimulating  conception  of 
atomic  and  molecular  structures  and  while 
there  are,  no  doubt,  a good  many  difficulties 
in  the  way  of  accepting  it  as  it  stands  there 
are  very  many  reasons  for  believing  it  to  be 
a much  closer  approximation  to  the  truth 
than  any  other  theory. 

High  Frequency  Spectra  of  the  Elements 

Within  the  present  year  Moseley,  working 
at  Manchester  University,  has  followed  up 
these  speculations  of  Bohr  by  actually 
determining  the  magnitude  of  the  nuclear 
charge  of  the  atoms  of  most  of  the  elements. 
When  the  atoms  of  any  element  are  bom- 
barded by  electrons  traveling  at  high  velocity, 
they  emit  characteristic  X-rays.  Bohr  showed 
that  there  is  a definite  relation  between  the 
charge  on  the  nucleus  of  these  atoms  and  the 
frequency  of  the  characteristic  X-rays  emitted. 
Moseley,  therefore,  made  the  different  ele- 
ments anti-cathodes  in  an  X-ray  tube,  thus 
bombarding  them  in  succession  with  cathode 
rays,  and  then  measured  the  wave-length 
of  the  X-rays  emitted.  For  this  purpose  he 
made  use  of  Bragg’s  method  of  reflecting 
the  rays  from  a rock-salt  crystal  and  photo- 
graphing the  resulting  diffraction  pattern. 
Knowing  the  distances  between  the  atoms 
of  the  rock-salt  cyrstal  and  the  angle  at 
which  the  X-rays  are  reflected  from  the 
surface  of  the  crystal,  it  is  possible  to  calculate 
their  frequencies. 

In  this  manner  Moseley  found  that  the 
relation  between  p,  the  frequency  of  the 
X-rays  emitted  by  the  bombarded  element 
and  N,  the  charge  on  the  nucleus,  is  given  by 
the  formula: 

v = A{N-BY 


GENERAL  ELECTRIC  REVIEW 


1202 

where  A and  B are  constants  for  each  set  of 
characteristic  rays.  He  has  determined  in  this 
manner  the  atomic  numbers  of  all  the  elements 
from  aluminum,  13,  to  gold,  79.  There  appear 
to  be  only  three  elements  in  this  range  which 
have  not  been  discovered  by  the  chemist. 
The  atomic  weight  thus  appears  to  have 
vastly  less  importance  than  the  atomic 
number.  In  fact,  as  stated  above,  there  may 
exist  two  or  more  elements  having  different 
atomic  weights  but  exactly  the  same  atomic 
number. 

Isotopic  Elements 

By  examining  the  very  high  frequency  radia- 
tion (gamma  rays)  emitted  by  radium  B and  by 
bombarding  lead  with  beta  rays  from  radium 
B,  Rutherford  has  found  that  both  these 
elements  give  the  same  characteristic  rays, 
indicating  that  they  have  the  same  atomic 
number,  82.  Now  so  far  as  their  chemical 
and  physical  properties  are  concerned,  the 
two  elements  behave  identically  the  same;  yet^ 
the  atomic  weight  of  lead  is  208,  while  that  oj 
Ra  B is  about  214-5- 

Lead  and  radium  B are  not  the  only 
examples  of  elements  that  differing  in  atomic 
weight  yet  occupy  the  same  place  in  the 
periodic  table.  Soddy  has  found  a number 
of  similar  cases  among  the  other  radio-active 
elements,  and  he  has  designated  them 
isotopes  (occupying  the  same  place).  These 
elements  are  absolutely  inseparable  by  all 
chemical  methods  derived  so  far;  yet  they 
differ  in  that  respect  which  has  hitherto 
been  taken  to  be  the  most  important  charac- 
teristic of  an  element — its  atomic  weight. 

It  that  is  true,  then  the  atomic  weight  of  a 
so-called  element  is  really  the  average  value 
of  the  atomic  weights  of  the  isotopes  of  which 
it  is  constituted,  and  ought  to  depend  upon 
the  particular  proportion  in  which  the 
isotopes  happen  to  be  present. 

In  agreement  with  this  conclusion  it  has 
recently  been  shown  by  Richards  and  Lem- 
bert^'^  that  lead  from  radio-active  sources 
has  an  atomic  weight  of  206.6,  whde  ordinary 
lead  has  an  atomic  weight  (determined  by  the 
same  method  in  parallel  analyses)  of  207.15. 
The  difference  is  much  greater  than  any 
possible  experimental  error.  It  must  further- 
more be  observed  that  both  specimens  of  lead 
are  identical  in  all  other  respects.  Thus,  both 
give  the  same  ultra-violet  spectrum. 

Is  Mass  Entirely  Electromagnetic  in  Origin  ? 

And  now  we  must  mention  briefly  one  more 
conclusion  which  is  probably  more  far  reach- 

>2Jour.  .A.m.  Chem.  Soc..  36,  1329  (July,  1914). 


ing  than  any  yet  deduced.  According  to 
Rutherford  and  Bohr,  the  nucleus  of  an  atom 
is  infinitesimally  small  compared  with  the 
dimensions  of  the  atom,  yet  practically  the 
whole  mass  of  the  atom  is  concentrated  m 
this  nucleus.  Now  let  us  quote  Rutherford 
himself. 

“It  is  well  known  from  the  expenments  of 
Sir  J.  J.  Thomson  and  others,  that  no  posi- 
tively charged  carrier  has  been  observed  of 
mass  less  than  the  hydrogen  atom.  The 
exceedingly  small  dimensions  found  for  the 
hydrogen  nucleus  add  weight  to  the  suggesticpn 
that  the  hydrogen  nucleus  is  the  positive 
electron,  and  that  its  mass  is  entirely  electro- 
magnetic in  origin.  According  to  the  electro- 
magnetic theory,  the  electrical  mass  of  a 

charged  body,  supposed  spherical,  is  g ^ ’ 

where  ^ is  the  charge  and  a the  radius.  The 
hydrogen  nucleus  consequently  must  have 
a radius  about  1/1830  of  the  electron  if  its 
mass  is  to  be  explained  in  this  way.  There  is 
no  experimental  evidence  at  present  contrary  , 
to  such  an  assumption. ' 

For  some  time  we  have  been  familiar  with 
the  idea  that  the  mass  of  the  negative  electron  , 
is  electromagnetic  in  origin ; if  the  same  holds  ^ 
true  for  the  positive  electron  or  hydrogen  ; 
nucleus,  then  we  are  forced  to  conclude  that  • 
all  matter  is  really  a manifestation  of  elec-  ' 
trical  charges  in  motion.  , 


In  the  above  remarks  an  attempt  has  been  f 
made  to  present  to  the  reader  in  a general  and 
confessedly  superficial  manner  sorne  of  those  j 
concepts  which  have  been  evolved  in  physical  j 
science  during  the  past  decade.  We  have  seen  : 
that  in  analogy  with  the  ordinary  atomic  | 
theory  of  the  structure  of  matter  there  has  j 
been  developed  not  only  an  atomic  theory  j 
of  electricity  but  also  one  of  energy. 

These  theories  are,  however,  not  to  be 
regarded  as  opposed  to  views  previously  held, 
but  rather  as  an  attempt  to  obtain  a deeper 
comprehension  of  the  innermost  mechanism 
of  natural  phenomena.  In  a word,  while  the 
physics  of  the  past  century  dealt  with  nature 
microscopically,  and  emphasized  the  idea  of  i 
continuity , the  physics  of  the  present  regards 
nature  microscopically  and  finds  that  under- 
neath the  apparent  continuity  there  exist 
distinct  discontinuities. 

For  the  chemist  as  well  as  physicist  a 
knowledge  of  the  investigations  which  have 

'3phil.  Mag.,  March,  p.  494  (1914). 


1203 


RECENT  VIEWS  ON  MATTER  AND  ENERGY 


led  to  these  new  speculations  are  of  extreme 
importance.  Objection  may  of  course  be 
raised  to  these  speculations  because  of  their 
obviously  hypothetical  nature.  The  argument 
may  be  advanced  that  since  the  theory  of 
today  is  apt  to  be  cast  aside  in  favor  of  the 
theory  of  tomorrow,  what  then  is  the  use  of 
any  theory  at  all  ? As  Royce  states 

If  certain  general  theories  are  mere 
conceptual  constructions,  which  today  are, 
and  tomorrow  are  cast  into  the  oven,  why 
dignify  them  by  the  name  of  philosophy? 
Has  science  any  place  for  such  theories?  * * * 
Why  not  say,  plainly:  Such  and  such  phenom- 
ena, thus  and  thus  described,  have  been 
observed;  such  and  such  experiences  are  to  be 
expected,  since  the  hypotheses,  by  the  terms 
of  which  we  are  required  to  expect  them, 
have  been  verified  too  often  to  let  us  regard 
the  agreement  with  experience  as  due  to 
merely  chance;  so  much  then  with  reasonable 
assurance  we  know;  all  else  is  silence— or  else 
is  some  matter  to  be  tested  by  another 
experiment?  Why  not  limit  our  philosophy 
of  science  strictly  to  such  counsel  of  resigna- 
tion? Why  not  substitute,  for  the  old  scientif- 
ic orthodoxy,  simply  a confession  of  ignorance 
and  a resolution  to  devote  ourselves  to  the 
business  of  enlarging  the  bounds  of  actual 
empirical  knowledge?  * * * “Why  not  ‘take 

^^Introduction  to  the  translation  of  Poincare’s  “Foundations 
oi  bcience. 


the  C3.sh  8,nd  let  the  credit  Why  pursue 
the  elusive  theoretical  unification  any  further, 
when  what  we  daily  get  from  our  sciences  is 
an  increasing  wealth  of  detailed  information 
and  of  practical  guidance? 

As  a fact,  however,  the  known  answer 
of  our  own  age  to  these  very  obvious  com- 
ments is  a constant  multiplication  of  new 
efforts  towards  large  and  unifying  theories.” 

The  scientific  investigator  overwhelmed 
with  numerous  observations  and  results  of 
experiments  in  different  fields  finds  an  actual 
need  for  some  unifying  conception  that  will 
make  it  easier  to  understand  the  manner  in 
which  all  these  varied  phenomena  are  corre- 
lated. 

The  scientific  imagination,  that  uncontrol- 
lable product  of  the  human  intellect,  can  no 
more  be  stifled  by  a rule  of  logic  than  freedom 
of  thought  could  be  repressed  by  any  theo- 
logical dogmas.  And  surely  it  is  worth  while 
to  make  an  error  occasionally  if  the  net  result 
be  an  increased  enthusiasm  and  inspiration 
to  increase  further  the  sum  of  human  knowl- 
edge. 

^ In^  conclusion,  the  writer  wishes  to  express 
his  sincere  appreciation  of  the  kindly  interest 
taken  in  this  paper  by  both  Dr.  W.  R. 
Whitney  and  Dr.  I.  Langmuir,  without  whose 
encouragement  and  inspiration  it  would 
not  have  been  attempted. 


1204 


GENERAL  ELECTRIC  REVIEW 


THE  ELECTRIFICATION  OF  CANE-SUGAR  FACTORIES 

By  a.  I.  M.  WiNETRAUB 
Engineer,  Zaldo  & Martinez,  Havana 

The  author  here  discusses  the  “steam  balance”  of  a sugar  factory,  as  well  as  the  points  of  superiority  of 
electric  motor  drive  over  steam-engine  drive.  By  “steam  balance”  is  meant  that  condition  obtaining  when  no 
more  steam  is  generated  than  needed  for  high-pressure  cooking  and  for  mechanical  power,  the  exhaust  from  the 
latter  being  sufficient  for  all  the  low-pressure  cooking  purposes.  In  the  economical  operation  of  a cane-sugar 
factory,  the  important  factor  is  rather  to  maintain  a “steam  balance”  than  simply  to  create  it.  This  can  be 
done  only  by  the  use  of  apparatus  which  provides  a means  of  regulating  a portion  of  the  steam  flow  to  suit 
momentary  conditions.  It  is  shown  that  the  only  apparatus  possessing  this  function  in  a satisfactory  degree 
is  a steam  turbine  of  the  extraction  type  coupled  to  an  electric  generator.  The  author  also  compares  steam 
drive  with  electric  drive  for  factory  power  and  shows  the  great  saving  in  favor  of  the  latter  method,  as  well  as 
the  reasons  for  its  greater  reliability,  thus  further  confirming  his  conclusions  that  only  by  electrification  can 
cane-sugar  factories  obtain  the  utmost  in  reliable  operation  and  financial  economy. — Editor. 


Another  very  satisfactory  season  of  electri- 
cally operated  cane-sugar  factories  has  just 
been  completed  in  Cuba;  and  while  the  pre- 
vious seasons  left  very  little  doubt  that  proper 
electrification  meant  an  unqualified  success, 
the  present  season,  beside  upholding  the  past 
record,  strengthens  the  conviction  that  the 
adoption  of  electric  drive  practically  imposes 
itself  upon  cane-sugar  factory  operation. 

Cuba  has  the  distinction  of  being  the 
pioneer  in  applying  the  alternating-current 
system  on  a large  scale  to  sugar  factories, 
and  the  results  obtained  have  been  so  gratify- 
ing and  convincing  that  foreign  countries 
have  followed  the  lead.  To-day  this  system  is 
being  introduced  in  Australia,  Hawaii,  and 
other  cane  growing  countries.  There  is 
hardly  an  owner  of  a sugar  factory  in  Cuba 
who  has  not  seen  at  least  one  of  the  electrified 
sugar  mills.  Of  the  replies  to  a circular  letter 
sent  to  sugar  mill  owners,  80  per  cent  were 
unconditionally  in  favor  of  electrification. 
This  statement,  made  by  the  interested  com- 
panies, is  in  itself  a fair  proof  of  the  satisfac- 
tory features  visibly  apparent  in  an  elec- 
trified factory,  but  the  engineer  can  obtain 
more  than  a superficial  proof  by  a careful 
analysis  of  the  conditions. 

The  advantages  obtained  by  the  electrifica- 
tion of  a cane-sugar  factory  are,  of  course,  not 
limited  to  fuel  economy  only,  although  this  lat- 
ter has  been  proved  to  be  in  itself  a very  con- 
siderable item.  As  will  be  shown  herewith, 
there  are  other  gains  equally  important  and 
far  reaching  in  insuring  uninterrupted  efficient 
operation  at  a reduced  cost  of  production. 

No  matter  whether  an  electrical  equip- 
ment is  being  selected  for  a new  sugar  house 
or  whether  the  problem  involves  the  electri- 
fication of  an  already  existing  steam-driven 
factory,  the  first  and  foremost  consideration 
should  be  that  of  creating  and  maintaining  a 
steam  balance.  The  steam  balance  in  a sugar 
factory  may  be  defined  as  the  condition  under 
which  live  steam  will  be  generated  to  an  extent 


only  sufficient  to  furnish  the  required  mechan- 
ical drive  and  that  ordinarily  necessary  for  the 
high-pressure  cooking  apparatus,  the  exhaust 
from  which  after  deducting  condensation  losses 
will  be  just  enough  for  the  ultimate  evaporation 
and  concentration  of  the  entire  dilute. 

In  an  already  existing  steam-driven  factory, 
with  probably  an  upset  steam  balance,  there 
is  another  very  important  consideration, 
viz.,  that  of  designing  an  equipment  which 
will  produce  and  maintain  the  steam  balance 
with  such  an  expenditure  of  money  that  the 
combined  interest  and  depreciation  of  the 
new  and  superseded  plant  will  be  more  than 
covered  by  the  total  economy  thus  secured.  ' 

There  still  are  a few  makers  of  sugar  factory  ; 
machinery  who,  although  admitting  that  in  an  : 
existing  steam-driven  factory  electrification  ■ 
can  show  a great  decrease  in  the  cost  of  pro- 
duction, are  skeptical  about  the  application  J 
of  electricity  to  newly  designed  factories.  , 
The  main  argument  they  advance  is  that  a 
steam  balance  can  be  created  in  a new  steam- 
driven  factory  when  properly  designed. 

While  it  may  be  true  that  a steam  balance  ; 
can  so  be  created,  it  will  be  shown  in  the  i 
following  that  an  electrical  equipment  having 
properly  designed  turbine-generators  is  the  ■ 
only  one  which  will  maintain  the  balance.  ) 
Furthermore,  such  advantages  as  reliability,  j 
ease  of  control,  cleanliness,  low  cost  of 
installed  equipment,  economy  of  lubrication, 
flexibility  of  installation,  reduced  operating 
expenses,  reduced  repair  expenses,  main- 
tenance of  cooking  apparatus  in  an  efficient 
state,  and  others  can  only  be  obtained  by 
the  use  of  an  adequate  electrical  equipment. 

In  an  ordinary  sugar  factory,  the  initial 
steam  pressure  at  the  engine  is  about  75  lb. 
gauge  per  square  inch  and  the  exhaust  about 
8 lb.  gauge  per  square  inch.  In  expanding 
one  pound  of  steam  from  this  initial  to 
exhaust  pressure,  the  engines  will  use  up 
therefore  918,000  — ■ 835,000  or  83,000  ft-lb., 
leaving  theoretically  available  in  the  exhaust 


THE  ELECTRIFICATION  OF  CANE-SUGAR  FACTORIES 


1205 


(assuming  no  condensation)  835,000  ft-lb., 
which  is  over  ten  times  the  energy  used  for 
mechanical  drive.  Usually  the  available 
heat  in  the  exhaust  steam  of  a sugar  factory 
is  at  least  seven  and  a half  times  that  used 
by  the  steam  engine  to  do  the  mechanical 
work,  and  with  ample  heat  protective  cover- 
ing may  be  even  eight  times  that  amount. 
This  fact  therefore  must  not  be  lost  sight  of, 
viz.,  that  by  far  the  greatest  portion  of  the  heat 
energy  contained  in  the  live  steam  appears  in 
the  exhaust  and  is"  not  used  for  mechanical 
drive.  After  a steam  balance  design  has 
been  arranged  to  give,  with  a certain  steam 
consumption  of  engines,  the  required  heat  for 
evaporation  in  the  form  of  exhaust  steam, 
every  additional  heat  unit  used  in  excess  for 
mechanical  drive  in  the  cylinders  of  the 
steam  engines  necessitates  the  release  of 
eight  heat  units  into  the  exhaust.  These  of 
course  will  be  wasted  if  the  balance  of  the 
steam  requirements  has  been  reached  before. 

With  a lack  of  steam  balance  it  is  sometimes 
necessary  to  employ  live  steam  for  cooking 
and,  at  others,  to  waste  exhaust  steam.  This 
means  taking  no  advantage  of  the  heat  units 
in  the  steam  for  mechanical  drive  in  the 
former  case  and  wasting  heat  units  in  the 
exhaust  in  the  latter  case. 

It  would  be  a comparatively  easy  matter 
to  obtain  a steam  balance  for  any  sugar 
house  if  the  milling  and  evaporating  con- 
ditions were  uniform  and  constant.  This, 
unfortunately,  is  not  found  to  be  so  in  practice 
for  both  the  mechanical  drive,  with  the  cor- 
responding exhaust  steam  production,  and 
the  requirements  of  evaporation  vary  due  to 
field,  yard,  and  factory  circumstances;  and, 
what  is  worse,  the  variations  are  independent 
of  each  other  and  may  not  occur  at  the  same 
time. 

Let  us  assume  that,  at  a certain  period  “B,” 
the  crushing  and  milling  engines  in  a steam- 
driven  factory  are  operating  at  full  load  and 
are  producing  an  exhaust  which  is  just  suffi- 
cient for  the  evaporation  of  the  juice  extracted 
and  diluted  some  time  before,  say  at  period 
“A,”  which  is  now  being  evaporated  at 
period  “B.”  If,  for  any  reason,  at  period 
“C,  ” the  milling  capacity  in  tons  per  hour 
is  reduced,  the  quantity  of  exhaust  steam  is 
also  reduced  due  to  the  lessened  mechanical 
load,  and  is  therefore  insufficient  for  the 
dilute  obtained  at  period  “B.”  In  this  case 
live  steam  would  have  to  be  employed  for 
evaporation.  On  the  other  hand  if,  at  period 
“C”,  the  load  increased  there  would  be  an 
excess  of  exhaust  steam  for  evaporating  the 


dilute  from  the  cane  crushed  at  period  “B,” 
which  would  result  in  a consequent  waste  of 
exhaust  steam. 

A still  better  illustration  of  this  condition  is 
available  in  a cane-sugar  factory  where  several 
tandem  grinding  rolls  are  operating. 

The  change-over  from  operating  one  or  two 
of  these  sets  at  a time  may  mean  an  excess  or  a 
lack  of  exhaust  steam  for  evaporating  the 
dilute  accumulated  before  the  change-over, 
and  the  steam  balance,  if  such  existed  pre- 
viously, is  thereby  upset. 

It  has  been  suggested  that  low-pressure 
turbine-generators  be  installed  to  utilize  the 
exhaust  steam  from  milling  engines  and  to 
have  electric  motors  drive  the  pumps  and 
other  mechanical  appliances  about  the  fac- 
tory. While  this  arrangement  appears  to  be 
satisfactory  to  a certain  extent,  it  implies  the 
use  of  large  condensers  in  connection  with  the 
turbine-generators  and  involves  the  feature 
of  evaporating  the  dilute  by  means  of  live 
steam;  for  with  such  an  arrangement  there 
would  be  no  exhaust  steam  available  for 
cooking.  This  would  call  for  a complete 
revolution  in  the  manufacture  and  operation 
of  cooking  apparatus.  The  suggestion  of 
utilizing  the  exhaust  steam  in  low-pressure 
turbines  has  been  originated  mainly  because 
of  the  desire  for  creating  and  maintaining  a 
steam  balance. 

There  have  also  been  other  suggestions  to 
eliminate  the  difficulties  attending  an  excess 
of  exhaust  steam,  most  of  which  apparently 
disregard  the  fact  that  instead  of  attempting 
to  utilize  in  one  way  or  another  the  heat  con- 
tained in  an  excess  of  exhaust  it  is  naturally 
more  logical  not  to  produce  this  excess  of 
exhaust  steam. 

The  problem  of  obtaining  maximum  fuel 
economy  can  unquestionably  be  solved  with 
such  an  equipment  as  will  give: 

(1)  Sufficient  exhaust  steam  for  cooking 
at  all  times. 

(2)  A variable  supply  of  exhaust  steam. 

(3)  A control  of  exhaust  steam  production 
to  give  only  the  needed  exhaust. 

(4)  An  automatic  governing  device  to 
make  the  exhaust  production  directly  pro- 
portional to  the  cooking  requirements. 

It  requires  no  special  effort  to  see  that  a 
sugar  house  which  is  equipped  to  fulfill  these 
conditions  will  take  care  of  all  requirements 
and  will  at  the  same  time  secure  a steam 
balance  with  its  consequent  ideal  fuel  economy. 

Extraction-type  steam  turbines  have  been 
used  quite  extensively  in  electric  power 
plants  for  furnishing  electric  light  and  power 


1206 


GENERAL  ELECTRIC  REVIEW 


and,  at  the  same  time,  supplying  exhaust 
steam  for  general  heating  purposes.  The 
conditions  in  a sugar  factory  are  not  material- 
ly different  from  those  just  mentioned  and 
there  is  absolutely  no  reason  why  such  an 
arrangement  when  suitably  adapted  to  a 
sugar  house  should  not  give  ideal  results. 

Fig.  1 is  a diagram  illustrating  the  principle 
involved  in  accomplishing  the  desired  end. 
The  letters  A illustrate  extraction-type  steam 
turbine-generators  which  have  their  exhaust 
lines  connected  to  a common  condenser.  An 
extraction  connection  is  shown  from  the 
first  stage  of  each  turbine  leading  into  a 
common  exhaust  receiver.  The  crushers  and 
mills  are  in  this  case  steam-driven  and  their 
exhaust  is  also  led  to  the  common  exhaust 
receiver.  Between  the  first  stages  of  the 
turbines  and  the  common  exhaust  receiver 
there  are  installed  automatically  operated 
valves  B,  which  are  interlocked  with  the 
valves  C.  Valves  B and  C are  set  in  such  a 
manner  that  when  the  pressure  in  the  exhaust 
receiver  is  maintained  at  6 to  8 lb.  per  square 
inch  or  higher,  valve  B is  shut  and  C is  wide 
open. 

With  such  an  arrangement,  let  us  assume 
that  the  crushing  and  milling  engines  are 


Fig.  1.  A Diagram  showing  an  Ideal  Arrangement  for  the 
Utilization  of  Steam  in  an  Electrified  Cane-Sugar  Factory 


furnishing  sufficient  exhaust  for  the  assumed 
cooking  requirements,  and  that  the  turbines 
are  operating  fully  condensing  which  gives 
high  fuel  economy.  When  the  demand  for 
exhaust  steam  in  the  cooking  apparatus  is 
greater  than  can  be  supplied  by  the  crushing 
and  milling  engines,  the  pressure  in  the 
exhaust  main  drops  and  automatically  opens 
valve  B and  closes  valve  C until  the  pressure 


in  the  main  exhaust  pipe  is  again  6 to  8 lb. 
At  this  time,  valve  B again  closes  and  the 
turbine  again  operates  condensing. 

Valves  B and  C can  be  designed  in  such  a 
manner  as  to  afford  a partially  opened 
B valve  with  a correspondingly  partially 
closed  C valve.  Then,  the  turbine  will 
operate  non-condensing  only  to  the  extent 
of  that  portion  of  the  steam  which  passes 
through  the  first  stage  and  is  then  extract- 
ed for  cooking,  while  the  remainder  of  the 
steam  taken  by  the  turbine  passes  through 
to  the  condenser  and  effects  a correspondingly 
economical  consumption. 

Since  the  exhaust  steam  from  operating  the 
crusher  and  grinding  rolls  is  never  sufficient 
for  the  entire  evaporation  of  the  dilute,  it  is 
advisable,  in  a sugar  factory  where  the 
crushers  and  rolls  proper  are  to  be  electrically 
operated,  to  have  one  non-extraction  turbine- 
generator  exclusively  for  the  mills  and 
crushers  and  to  have  another  one  or  two 
turbine-generators  of  the  extraction  type  to 
compensate  for  the  lack  or  excess  of  exhaust 
steam  as  described.  The  non-extraction  tur- 
bine-generator should  have  a capacity  equal 
to  about  50  per  cent  of  the  total  mechanical 
drive  in  the  factory  and  should  operate  non- 
condensing, its  exhaust  steam  being  carried 
into  the  exhaust  receiver  just  as  in  the  case 
of  the  steam-driven  crushers  and  mills. 

The  turbines  operate  normally  non-con- 
densing, feeding  their  exhaust  steam  into  the 
exhaust  pipe  line  for  evaporation  of  the 
dilute.  When  the  quantity  of  exhaust  steam 
exceeds  the  requirements,  the  pressure  in  the 
exhaust  line  rises  and  operates  a valve  which 
diverts  the  excess  exhaust  steam  into  the 
condenser.  If  the  quantity  of  exhaust  steam 
from  the  turbine  is  insufficient  for  the  cooking 
requirements,  the  pressure  in  the  exhaust 
pipe  line  drops  and  the  valve  is  operated 
automatically  in  such  a manner  that  more 
exhaust  steam  is  fed  into  the  exhaust  line  and 
less  is  diverted  into  the  condenser.  When  all 
the  steam  exhausted  from  the  turbine  is 
required  in  the  exhaust  pipe  line,  the  valve 
opens  wide,  the  condenser  connection  is 
automatically  shut,  and  the  turbine  operates 
non-condensing . 

Fortunately,  when  operating  entirely  non- 
condensing, with  as  low  a steam  pressure  as 
the  80  lb.  per  square  inch  that  is  available  in 
most  sugar  mills,  and  exhausting  at  about  6 to 
8 lb.,  the  steam  turbine  consumes  over  twice 
as  much  steam  as  when  exhausting  into  a 
26-in.  vacuum.  This  is  decidedly  a favorable 
feature  in  the  operation  of  a sugar  factory. 


THE  ELECTRIFICATION  OF  CANE-SUGAR  FACTORIES 


1207 


for  the  arrangement  described  can  furnish  the 
factory  with  enough  exhaust  steam  to  fulfill 
its  maximum  requirements  and,  when  not  as 
much  is  required,  the  portion  of  steam  that 
is  not  needed  is  condensed  and  effects  the 
operating  efficiency  corresponding  to  the 
vacuum  in  the  condenser. 

The  proper  control  of  the  electrically- 
driven  air  and  injection  pumps,  that  serve 
the  auxiliary  condenser  which  operates  in  con- 
nection with  the  extraction  turbines,  can  be 
obtained  by  automatic  starting  and  stopping 
devices  that  are  governed  by  the  valves  B 
and  C.  Similar  arrangements  can  be  made 
in  case  the  exhaust  from  the  turbines  should 
be  carried  to  the  central  condenser,  or  man- 
ually by  means  of  signals  operated  by  the 
valves  B and  C. 

In  the  suggested  layout  the  feature  which 
will  undoubtedly  arrest  the  engineers’  atten- 
tion is  the  one  pertaining  to  the  operation 
of  the  extraction  turbine  at  times  under  a 
vacuum  with  the  consequent  necessitated  use 
of  a condenser  and  additional  cooling  water. 

If  it  is  remembered,  however,  that  the 
vacuum  may  be  as  low  as  25-in.  and  still  give 
decided  advantages  and,  above  all,  that 
the  turbine  condenser  is  an  emergency  equip- 
ment which  is  to  operate  only  when  the 
steam  balance  is  endangered,  and,  if  it  is 
further  remembered,  that  the  condenser  is  to 
take  care  of  only  a part  of  the  steam  input  to 
the  turbine,  it  will  be  readily  appreciated 
that  the  size  of  the  condenser,  the  water  it 
requires,  and  the  attention  to  its  auxiliaries 
are  of  very  little  importance  compared  with 
the  enormous  advantages  to  be  derived. 

It  must  always  be  kept  in  mind  that  when 
steam  is  extracted  in  the  manner  suggested, 
from  the  first  stage  of  a turbine,  it  has  been 
used  efficiently  in  the  first  stage  for  producing 
power,  and  the  steam  which  passes  through 
the  remaining  stages  has  been  used  on  the 
regular  condensing  basis  of  efficiency  and 
therefore  the  arrangement  when  taken  as  a 
whole  is  very  efficient. 

Knowing  that  the  condenser’s  duty  is 
mostly  to  condense  the  excess  of  exhaust 
steam  and  this  on  the  basis  of  vacuum  effi- 
ciency, it  will  at  once  appear  that  the  quantity 
of  steam  to  be  taken  care  of  and  therefore  the 
condenser  required  are  not  of  alarming 
proportions. 

In  most  cases,  it  will  probably  be  possible 
to  connect  the  vacuum  end  of  the  extraction 
turbine  to  the  main  condenser  of  the  sugar 
factory  so  that  the  additional  requirements 
would  be  reduced  to  pumping  only  a little 


more  cooling  water  and  operating  the  air 
pump  a little  faster. 

To  correct  for  a steam  balance  in  a 1000-bag 
per  day  sugar  factory  which  consumed  about 
80,000  lb.  of  live  steam  per  hour  and  which 
was  unbalanced  to  the  extent  of  wasting  as 
much  as  18,000  lb.  of  exhaust  per  hour,  it  has 
been  found  that  with  the  installation  of  only  a 
300-kw.  extraction  turbine  the  otherwise 
wasted  exhaust  steam  could  be  made  available 
to  evaporate,  in  the  effects  and  vacuum  pans, 
some  30,000  lb.  of  maceration  water*  which  in 
the  case  under  consideration  meant  over  20 
per  cent  maceration  on  cane.f  In  this  case 
some  350  horse  power  of  steam  engines  could 
be  replaced  by  electric  motors  which  would 
eliminate  that  amount  of  unnecessary  exhaust, 
there  being  an  excess  of  exhaust  steam  in  the 
factory ; and  a steam  balance  could  be  obtain- 
ed with  an  extraction  of  almost  5,000  lb.  of 
steam  from  the  turbine. 

With  this  turbine,  requiring  about  12,000 
lb.  of  steam  at  the  throttle  (80  lb.  initial,  6 lb. 
back  pressure)  and  operating  with  5,000  lb. 
extraction,  the  size  of  the  condenser  for  26  in. 
vacuum  need  therefore  be  of  a capacity  to 
take  care  of  only  7,000  lb.  of  steam  per  hour, 
which  is  indeed  not  of  a size  to  give  any 
serious  concern. 

It  is  to  be  noted  in  the  diagram  of  the  sug- 
gested arrangement  of  steam-driven  crush- 
ing and  milling  engines.  Fig.  1,  that  the 
boilers  operating  the  extraction  turbine-gen- 
erators (and  which  are  intended  for  all 
mechanical  drive  excepting  the  mill  drivers 
proper)  are  shown  to  be  separate  from  the 
boilers  intended  for  the  milling  engines 
proper.  This  of  course  does  not  mean  that 
new  boilers  are  required  in  an  already  existing 
steam-driven  factory  that  is  to  be  electrified, 
or  that  additional  boilers  than  would  other- 
wise be  required  are  needed  for  a new  plant 
to  be  installed  along  the  lines  suggested. 

* To  best  explain  the  expression  "maceration  water"  it  is 
deemed  advisable  to  quote  the  following  from  authorities  on 
the  subject: 

"When  water  is  poured  on  the  bagasse  the  residual  juice  in 
the  bagasse  is  diluted,  and  after  recrushing  the  bagasse  to  its 
former  content  of  juice,  it  will  contain  the  same  amount  of 
dilute,  but  therefore  less  saccharine,  causing  less  loss  of  sugar, 
so  that  maceration  considerably  improves  the  juice  extraction. 
(H.  C.  Prinsen  Geerligs,  1909,  "Cane-Sugar  and  its  Manufac- 
ture.")" 

"At  the  present  time  two  schemes  are  employed  in  washing 
out  sugar  from  the  bagasse;  in  the  one  which  is  sometimes  dis- 
tinguished as  imbibition,  water  preferably  hot  is  sprayed  on  the 
bagasse  as  it  leaves  one  mill;  in  the  other  known  as  maceration 
the  partly  exhausted  bagasse  is  drawn  through  a bath  kept 
with  diluted  juice  which  has  already  been_extracted.  (Noel 
Deerr,  1905,  "Sugar  and  the  Sugar  Cane.")" 

t The  degree  of  extraction  is  often  conveyed  by  speaking  of 
the  percentage  of  maceration  water  as  compared  to  the  total 
weight  of  cane  ground.  In  this  case  "20  per  cent  maceration 
on  cane"  means  that  the  weight  of  water  added  was  20  per  cent 
of  the  total  weight  of  the  cane  ground. 


1208 


GENERAL  ELECTRIC  REVIEW 


Generally  speaking  of  the  total  boiler 
capacity  of  a cane-sugar  factory,  50  per  cent 
furnishes  steam  for  the  mills  proper  and  50 
per  cent  for  the  other  drivers  about  the  plant ; 
and  it  is  possible  to  divide  the  total  intended 
capacity  of  the  boilers  into  batteries  so  that 
each  may  take  care  of  their  apportioned 
duties. 

The  most  likely  reason  causing  a drop  in 
boiler  pressure  is  the  variable  load  on  the 
crushing  and  milling  engines  and  if  the 
boilers  feeding  them  are  separate  from  the 
other  drivers,  the  load  on  which  is  practically 
constant,  there  will  be  the  consequent  advan- 
tage of  constant  steam  pressure  to  the  turbine- 
generator  that  is  to  operate  the  electric 
motors,  a feature  which  is  by  all  means 
desirable. 

It  is  of  course  appreciated  that  with  a 
variable  load  on  the  mills  proper  the  quantity 
of  bagasse  and  its  quality  are  variable  and 
therefore  this  has  a bearing  on  the  pressure  of 
the  boilers  assigned  to  the  electric  drive,  but 
it  is  practicable  indeed  to  arrange  for  the 
bagasse  supply  in  such  a manner  that  con- 
stant pressure  may  be  maintained  on  the 
“electric”  boilers  with  a constant  fuel  supply. 

It  has  been  claimed  in  this  paper  that  the 
steam  balance  can  be  maintained  only  with  a 
properly  designed  turbine-generator  equip- 
ment. 

In  no  sugar  factory  will  conditions  remain 
absolutely  invariable  from  crop  to  crop  as 
regards  steam  consumption,  and  a steam 
balance  once  created  in  such  a factory  has  a 
tendency  to  be  upset  by  the  addition  or 
deduction  of  machinery. 

If,  instead  of  using  turbine-generators  of  the 
extraction  type,  we  should  attempt  to  use 
compound  or  triple  expansion  units  with  the 
intermediate  or  low-pressure  cylinders  acting 
as  “stages”  in  the  same  manner  as  the  stages 
of  an  extraction  turbine,  it  would  perhaps 
be  possible  to  make  arrangements  in  such  a 
manner  that,  in  accordance  with  demanded 
requirements,  the  intermediate  and  low  pres- 
sure cylinders  may  be  by-passed  and  steam 
thereby  be  exhausted  at  a higher  or  lower 
pressure  for  cooking  or  even  below  atmosphere 
to  the  condenser.  This,  however,  would 
mean  driving  the  pistons  of  the  corresponding 
cylinders  “dry,  ” or  without  steam  at  times,  a 
feature  which  is  by  no  means  advisable. 

As  can  be  seen,  the  variable  quantity  of 
low-pressure  steam  is  not  obtainable  there- 
fore with  a piston-type  steam  driver  and 
the  steam  balance  which  has  as  a basis  just 
this  condition  is  only  obtainable  from  a stage- 


type  rotary  steam  unit  with  an  extraction 
arrangement  such  as  the  Curtis  extraction- 
type  turbine. 

The  manager  of  an  important  factory  in 
Cuba  which  has  an  output  of  about  150,000 
bags  of  sugar  per  season  calculated  that  inter- 
ruptions in  his  mill  represent  $6.00  per 
minute,  or  over  $8000  per  actual  milling 
day.  This  should  amply  indicate  the  impor- 
tance of  uninterrupted  operation  in  a sugar 
factory  and  it  only  remains  to  show  that  the 
electric  motor  affords  protection  against 
such  interruptions. 

Excluding  the  mill  drivers  proper,  crystal- 
izers,  and  centrifugals,  the  most  important 
drive  in  a sugar  factory  is  practically  that 
required  for  pumping  only.  All  pumping, 
with  the  exception  of  that  for  masse-cuite 
and  molasses,  can  and  should  be  done  by 
centrifugal  pumps  due  to  their  lack  of  valves 
and  reciprocating  motion.  Pump  inter- 
ruptions are  due  mainly  to  the  sticking  or 
breaking  of  valves  and  to  the  failing  of  the 
cylinder  lubricating  system.  The  centrifugal 
pump  eliminates  these  difficulties  entirely 
because  it  has  no  valves  and  does  not  require 
internal  lubrication.  The  advantages  to  be 
derived  from  using  high-speed  pumps  of  this 
type  are  therefore  obvious.  The  benefits  of 
simplicity  and  reliability  which  are  obtained 
by  the  use  of  centrifugal  pumps  are  easily 
augmented  by  the  adoption  of  electric  motor 
drive.  Furthermore,  an  electric  motor  would 
be  the  logical  selection  for  driving  a centri-  | 
fugal  pump,  since  both  are  naturally  high- 
speed machines  and  can  be  coupled  together 
directly. 

As  to  the  application  of  electric  motors  to  : 
the  pumping  of  masse-cuite  and  molasses,  j 
steam  troubles  are  avoided  inasmuch  as  no  i 
complicated  oiling  system  or  close  attention  | 
is  required  with  electric  motors;  and  this  of  j 
course  also  holds  true  for  the  other  drives  | 
about  the  factory,  such  as  crystalizers, 
centrifugals,  blowers,  conveyors,  air  pumps,  etc. 

With  the  advent  of  the  new  rotary  air  I 
pump,  the  application  of  the  electric  motor 
becomes  still  more  universal;  and  there  is 
really  no  drive  where  the  electric  motor 
could  not  show  superior  operating  character- 
istics, a decreased  measure  of  attention 
required,  and  a greater  degree  of  continuity 
of  operation. 

From  a very  carefully  controlled  sugar 
factory  in  Cuba  producing  1100  bags  of 
sugar  of  325  lb.  each  per  day  of  23  hours,  a 
careful  analysis  of  the  results  furnished  the 
following  data. 


THE  ELECTRIFICATION  OF  CANE  SUGAR  FACTORIES 


1209 


The  total  cost  of  the  extra  fuel  purchased 
during  the  crop  season  of  160  days  was 
$20,000. 

The  live  and  exhaust  steam  piping  for  the 
small  engines  and  pump  connections  only  was 
found  to  have  over  7500  square  feet  of 
radiating  surface  and  the  value  of  fuel  being 
taken  at  25  cents  per  million  B.t.u.  or  about 
$7.00  per  ton  of  coal  equivalent,  it  was  cal- 
culated that  over  $4,000  was  lost  in  radiation 
and  condensation  per  crop,  which  represents 
20  per  cent  of  the  amount  spent  for  extra  fuel. 

The  piping  mentioned  takes  care  of  approxi- 
mately 1500  h.p.  in  engines  and  assuming, 
when  electrified,  a wiring  loss  of  2}/2  per  cent, 
which  is  indeed  reasonable  when  considering 
a properly  distributed  alternating-current 
installation,  we  have  a loss  of  37.5  h.p. 

With  a consumption  of  25  lb.  of  steam  per 
horse  power  hour  lost,  the  steam  loss  per 
season  of  160  days  of  23  hours  each  would  be 
3,450,000  lb. of  steam. 

Assuming  that  with  $7.00  worth  of  fuel 
we  can  produce  19,000  lb.  steam  ($7.00  per 
ton  of  coal) , the  cost  of  the  lost  power  would  be 


3,450,000X7 

19000 


= $1270 


Considered  against  the  $4000  this  shows  a 
difference  of  $2730  which  represents  a saving 
of  over  13)/^  per  cent  of  the  purchase  of  extra 
fuel. 

On  the  basis  of  conditions  as  found  in  the 
sugar  factory  referred  to,  further  comparison 
has  been  made  relative  to  the  labor  and  inci- 
dental material  expense. 


Steam 

Electric 

Labor  expense  during 

crop,  per  day .... 

$65.19 

$26.55 

Labor  exp.  lay-by, 
endof  crop, per  day 
Labor  expense  pump- 

2.79 

0.28 

ing  station 

3.33 

0.00 

$71.31 

$26.83 

Or,  atotalfor  IbOdays 

$11,409.60 

$4292.80 

Labor  balance  in  favor  of  electric  drive  . . . 

$7116.80 

The  lay-by  labor  expenses  at  the  end  of  the 
crop  are  due  to  dismounting  the  machinery  and 
coating  it  with  non-rusting  material  to  protect 
it  while  standing  idle  for  200  days. 

The  labor  expense  of  the  pumping  station 
is  due  to  the  fact  that,  in  the  case  of  this 
steam  sugar  factory,  it  is  necessary  to  have  a 
small  pumping  station  at  a distance  of  one 
mile  from  the  factory,  a condition  which 
applies  to  practically  all  sugar  mills  in  Cuba. 


The  time  lost  in  starting  the  engines  when 
stopped  on  dead  center,  in  slow  acceleration, 
and  in  other  general  features  which  would 
cause  complete  shut  down  of  the  mills  proper 
can  be  assumed  to  be  four  minutes  daily  at 
$6.00  per  minute,  or  a total  of  $3,840  for  a 


Steam 

Electric 

Material  for  repair- 
ing pipe  coverings 
per  crop  day. . . . 

$1.25 

$0.06 

Material  for  piston 
packing,  lubrica- 
tors, spares,  etc., 
per  crop  day .... 

19.87 

1.10 

Paint,  painting  tools 
and  labor  per 
crop  day  

1.20 

0.12 

Oil  and  grease  per 
crop  day 

13.83 

2.50 

Cotton  waste  per 
crop  day 

1.87 

0.60 

Repairs  and  oil  at 
pumping  station 
per  crop  day. . . . 

0.25 

0.10 

Or,atotalforl60days 

$38.27 

$6,123.20 

.$4.48 

$716.80 

Material  balance  in  favor  of  electric  drive . 

$5,406.40 

crop  of  160  days.  This  item  is  not  chargeable 
to  the  “electric”  column. 

To  resume,  we  have  in  favor  of  electrified 
sugar  factories  the  following  items: 


(A)  Saving  in  transmission 

losses 

$ 2,730.00 

(B)  Saving  in  labor 

(C)  Saving  in  incidental 

7,116.80 

material 

5,406.40 

(D)  Saving,  interruptions 

3,840.00 

Total .... 

$19,093.20  per  crop. 

The  values  given  in  the  “steam”  column 
are  amounts  actually  spent  in  the  sugar 
factory  under  consideration,  while  the  ones 
in  the  “electric”  column  are  computed 
values  from  carefully  analyzed  obtainable 
conditions  during  a crop  of  160  days  with  an 
assumed  electrical  layout  and  quite  liberal 
help.  It  should  be  noted  that  the  comparison 
is  made  on  the  basis  of  all  drives  other  than 
for  mills  proper,  which  latter  have  in  this 
case  been  assumed  to  be  steam  driven. 
Remembering  now  that  the  factory  makes 
1100  bags  of  sugar  per  day  or  about  175,000 
bags  per  season,  the  saving  just  mentioned, 
which  it  must  be  recalled  is  exclusive  of 
fuel  economy,  represents  almost  11  cents  per 
bag  of  sugar  or  over  2 per  cent  of  the  average 


1210 


GENERAL  ELECTRIC  REVIEW 


value  at  which  a bag  of  sugar  was  sold  in 
Cuba  during  the  last  crop. 

The  fact  must  not  be  lost  sight  of  that 
these  data  as  obtained  apply  to  an  exception- 
ally well  managed  factory  and  that  the 
advantages  of  an  electric  drive  over  the 
average  steam  drive  will  be  decidedly  greater 
than  the  ones  just  shown. 

The  exhaust  steam  from  a turbine-generator 
contains  no  oil,  as  is  the  case  with  the  recip- 
rocating engine;  and,  if  turbine-generators 
are  used  in  a cane-sugar  factory,  the  heating 
coils  and  the  calandria  of  the  evaporating 
apparatus  will  receive  no  heat-insulating  oil 
coatings.  It  is  well  known  that  the  efficiency 
of  the  cooking  apparatus  in  cane-sugar 
factories  is  greatly  impaired  by  such  scales, 
the  transfer  of  heat  from  the  exhaust  steam  to 
the  liquor  being  greatly  diminshed.  Any 
arrangement  which  will  avoid  the  forming 
of  such  scales  and  which  will  maintain  the 
heating  surfaces  in  a maximum  heat  trans- 


mitting condition  must  be  productive  of 
economy  not  only  in  time  and  fuel  but  also  in 
maintenance  cost  of  the  heating  apparatus. 

With  a properly  designed,  well  constructed 
and  installed  turbine-generator  equipment,  it 
is  undoubtedly  possible  to  obtain  at  least 
an  additional  34  per  cent  yield  due  to  the 
possibility  of  increased  maceration ; and  in  the 
mill  under  consideration  an  1134  per  cent 
yield  could  be  obtained  instead  of  an  11  per 
cent.  This  represents  an  increased  revenue 
of  234  per  cent  which,  translated  into  dollars 
and  cents  on  the  basis  of  last  crop’s  average 
prices  (3^  reales  per  arroba;  i.e.,  approxi- 
mately 2 cents  per  lb.),  means  an  extra  income 
of  $19,775.  Outside  of  the  saving  in  fuel 
it  may  be  expected  therefore  that  a proper 
electrification  of  this  mill  should  produce  a 
saving  of  about  $40,000,  which  in  itself  is 
indeed  a respectable  sum  to  pay  for  interest 
and  depreciation  on  an  electrified  mill  to  cover 
the  new  and  superseded  machinery. 


NOTES  ON  THE  USE  OF  THERMO-ELECTRIC  APPARATUS  IN 
HIGH  FREQUENCY  SYSTEMS* 

Part  II 

By  August  Hund 

Research  Laboratory,  General  Electric  Company 

This  article  is  a continuation  of  one  which  appeared  under  the  same  title  in  the  October,  1914,  issue  of 
the  Review.  The  present  installment  deals  with  different  combinations  of  thermo-elements,  such  as  the 
thermo-cross  and  the  three-thermo-cross  methods,  which  provide  sensitive  means  of  determining  the  reaso- 
nance  curve  and  the  logarithmic  decrement  of  a circuit.- — Editor. 


The  actual  dissipation  of  energy  in  A , 
Fig.  9,  is 

W=V.l2  (31) 

If  only  the  thermo-couples  I and  III  are 
used,  the  deflection  of  the  galvanometer 
will  be 


a = K . I,.  I 


(32) 


= K^  |^V./2+(Ei./2+|(V+ri)^J 


This  shows  that  the  indicated  energy  is 
larger  by  the  quantity 

2 


K 


i 


Since 


V 1 . I2 

F+  Li 


’) 


C = 


R 


we  obtain  the  expression  for  the  deflection 
of  the  wattmeter  as  follows: 

« = I FI2+ |^Fi./2+-2“]  I (33) 

The  correction  factor,  j^Ei.l2+— “ 

must  be  separately  determined  for  each  value  ^ 
of  the  energy  to  be  measured.  This  can  be 
done  automatically  by  the  addition  of  the  two 
thermo-couples,  II  and  IV,  as  shown  in  Fig. 

9.  The  thermo-couples  I and  III  would 
measure  the  energy  according  to  equation 
(33).  The  thermo-couple  IV  measures  the 
energy  \\  L;  and  the  thermo-couple  II,  if 
made  half  as  sensitive  as  the  other  thermo- 

R.Iv‘' 

couples,  will  measure  the  energy  • Then 


* ERRATUM. — The  title  for  Fig.  6 which  occurred  in  Part  I of  this  article.  General  Electric  Review, 
October,  page  986  should  have  read  as  follows: 

“Fig.  6.  The  Thermo-couple  system  shown  in  Fig.  2 shunted  to  measure  heavy  currents.  When  a proper 
value  of  self-inductance  is  used  in  the  two  branches,  the  system  will  give  accurate  readings  at  any  frequency.” 


THERMO-ELECTRIC  APPARATUS  IN  HIGH  FREQUENCY  SYSTEMS  1211 


by  properly  connecting  these  thermo-couples, 
as  shown  in  Fig.  9,  the  actual  energy  can  be 
measured  directly. 

The  following  is  a description  of  a recent 
application  of  the  thermo-cross  bridge  to  the 
measurement  of  resonance  and  to  the  determi- 
nation of  the  logarithmic  decrement.  This 
determination  has  usually  been  carried  out 
by  the  method  of  Bjerkness,  in  which  either 
the  self-induction  or  the  capacity  of  the 
circuit  is  varied  until  the  current  becomes  a 
maximum  at  resonance.  Such  a Bjerkness 
curve  is  represented  by  the  expression 
00 

dt  = function  (X)  (34) 

0 

where  X is  the  wave  length  and  i^  the  instan- 
taneous value  of  the  current  in  the  resonator 
circuit.  It  is  essential  that  the  energy  of  the 
oscillator  circuit  (Fig.  10)  be  kept  absolutely 
constant  since  any  variation  in  it  affects  the 
current  indicator  in  the  resonator  circuit. 
In  order  to  overcome  this  objectionable 
feature,  L.  Mandelstam,  N.  Papalexi  and 
others*  worked  out  an  improvement  by  caus- 
ing both  the  oscillator  and  the  resonator 
currents  to  act  on  the  indicator. 

Their  resonance  curve  is  represented  by 

CO 

ii.i^  dt  = function  (X)  (35) 

0 


Fig.  9.  A Scheme  of  Connections  which  is  an  Improvement 
over  that  shown  in  Fig.  8 


where  A and  A are  the  instantaneous  values 
of  the  current  in  the  oscillator  and  resonator 
circuits,  respectively.  These  are  defined  by  the 
equations 

ii  = Io\€  ^ sin  (2  tt  ft-\-'^i) 

A = /026  ^ sin  (2  7T  ft  + '^i). 

In  the  theory,  as  worked  out  by  Mandelstam 


and  Papalexi,  it  is  shown  that  resonance  takes 
place  when 

f-  . 

I i\_A2dt  = (), 


c 


Fig.  10.  A Scheme  of  Connections  for  Applying  the  Thermo- 
Cross  Bridge  to  Determine  the  Resonance  Curve 
of  Circuit  1 and  to  Measure  the  Logarithmic 
Decrements  of  Circuits  1 and  2 

at  which  time  the  currents  A and  A have  a 
phase  displacement  of  about  4^1  — 4^2  = 90 
degrees  with  respect  to  each  other.  The  reso- 
nance curve  reaches  its  maximum  for  a definite 
amount  of  tuning,  which  is  dependent  on  the 
decrement  of  the  resonator  and  oscillator 
circuit.  Since  this  is  a zero-method,  it  is 
inherently  independent  of  the  energy  varia- 
tions in  the  oscillator  circuit,  and  is  obviously 
therefore  preferable  to  the  previously  de- 
scribed Bjerkness  method.  In  place  of  the 
short-circuit-ring-dynamometer,  which  is  used 
for  the  current  indicator  in  the  Mandelstam 
and  Papalexi  method,  a thermo-cross  bridge 
may  be  substituted,  thus  procuring  a con- 
siderably higher  sensibility  in  range,  accuracy 
and  ease  in  manipulation. 

In  order  to  illustrate  this  method  the  dia- 
gram of  connections  is  given  in  Fig.  10.  The 
currents  if  and  A^  have  practically  the  same 
phase  difference  as  A and  A of  the  oscillator 
and  resonator  circuits  (if  the  coupling  induct- 

*L.  Mandelstam  and  N.  Papalexi,  Ann.  d.  Phys.,  33,  1910, 
M.  Dieckman,  Diss.  Strassburg,  1907. 

H.  Rohmann,  Diss.  Strassburg,  1911, 

L.  Kann,  Phys.  Z.,  12,  1911, 

L.  Isakow,  Phys.  Z.,  12,  1911. 


1212 


GENERAL  ELECTRIC  REVIEW 


ances  are  small).  The  galvanometer  deflection 
a becomes 


00 

dt 

0 


00 

dt 

0 


(36) 


Fig.  11.  A Resonance  Curve  taken  with  the  Method 
Shown  in  Fig.  10 


Since 


^ CO  ^ CO  ^ CD 


A representative  resonance  curve  as  obtained 
by  this  method  is  given  in  Fig.  11.  The 
deflections  of  the  galvanometer  are  plotted 


against  100 


C-Cr 

Cr  ' 


where  Cr  is  the  value  of 


the  capacity  at  resonance  and  C is  the  value 
of  the  capacity  when  the  resonator  circuit  is 
not  in  tune  with  the  oscillator.  It  will  be 
noted  that  the  curve  is  very  slanting  at  the 
point  of  resonance.  It  is  evident,  therefore, 
that  this  method  is  very  sensitive  since  a very 
small  change  in  the  capacity  C corresponds 
to  a considerable  variation  in  the  integral 
value 


J. 


dt. 


Another  combination  of  thermo-elements 
which  can  be  used  for  measuring  the 


values  of  two  oscillating  circuits  is  due  to 
M.  Dieckmanf,  who  arranged  three  thermo- 
crosses as  shown  in  Fig.  12.  In  this  method 
the  thermo-elements  J,  II  and  III  are 
connected  in  series  with  a galvanometer,  and 
the  connections  are  so  made  that  the  effects 
of  J and  II  are  additive  and  III  is  subtractive. 
The  electromotive  force  of  each  thermo- 
element is  as  follows: 

I is  directly  proportional  to 
II  is  directly  proportional  to 
III  is  directly  proportional  to  (Mifi+W2f2)^. 

The  values  of  ni  and  «2  depend  upon  the  ratio 
of  the  coupling  turns  in  the  oscillator  and 
resonator  circuits,  respectively.  With  these 
connections  one  is  able  to  obtain  galvanometer 
deflections  which  are  proportional  to 


f 


CO 

dtj 

0 


OsciHotor  /Resonator 


Fig.  12.  A Scheme  of  Connections  using  a Combination  of 
Three  Thermo-Couples  to  Determine  the  Resonance  Curve 
of  Circuit  1 and  to  Measure  the  Lrogarithmic 
Decrements  of  Circuits  1 and  2 

since 


where  a.  is  the  galvanometer  deflection  and 
^ is  a constant. 

fM.  Dieckman,  1.  c. 


THERMO-ELECTRIC  APPARATUS  IN  HIGH-FREQUENCY  SYSTEMS  1213 


The  curve  marked 


OO 

A-^2  dt 

0 

in  Fig.  13  is  plotted  from  the  results  obtained 
by  this  method.  The  abscissae  are  degrees 
on  the  scale  of  the  condenser  which  is  inserted 
in  the  resonator  circuit  and  the  ordinates  are 
deflections  of  the  galvanometer.  The  Bjerk- 
ness  curve, 

OO 

dt, 

D 

is  also  shown  in  Fig.  13  in  order  to  facilitate 
comparison  between  the  two  methods.  This 
latter  resonance  curve  is  the  plot  of  data  as 
secured  by  means  of  an  ordinary  thermo- 
couple, such  as  is  shown  in  Fig.  2.  The 
couple  was  inserted  in  a separate  circuit  which 
was  loosely  coupled  to  the  resonator.  It  is 
well  to  note  that  the  maximum  point  of  the 
Bjerkness  curve  comes  at  exactly  the  same 
abscissa  as  the  zero  point  of  the 
00 

. t2  dt  curve. 

0 


In  this  section  a short  discussion  on  the 
measurement  of  the  logarithmic  decrement 
will  be  given  in  order  to  point  out  the  wide 
field  of  application  of  the  thermo-cross  bridge 
and  the  three-thermo-couple  method.  The 
sum  of  the  logarithmic  decrements  may  be 
computed  from  an  ordinary  resonance  curve, 
such  as  the 

00 

dt 

curve  of  Fig.  13,  from  the  formula 


Al“h  A2  — 7T. 


= 7T.- 


Cr-C 

C 

Cr-C 

C 


a!' 

I « 

\ar  — a 


2_  r 2 


(38) 


In  this  formula  Ai  and  A2  are  the  logarithmic 
decrements  of  the  circuits  1 and  2 respectively 
of  Fig.  12,  a is  the  deflection  of  the  galva- 
nometer which  is  proportional  to 

00 

dt 

and  corresponds  to  the  value  C of  the  capacity 
which  is  in  circuit  2,  and  a.r  corresponds  to  Cr 
at  which  value  the  circuit  2 is  in  resonance 
with  circuit  1.  If  the  corresponding  wave 


lengths  X and  be  introduced,  equation  (38) 
would  become 

Ai+A2  = 2 (38a) 


ing  to  the  Method  shown  in  Fig.  12,  is  shown  compared 


with  Curve 


J tV  dt. 


which  is  plotted  from  data 


obtained  by  the  Ordinary  Bjerkness  Method 


If  the  logarithmic  decrements  are  to  be 
determined  from  the 


J 


00 

. 22  dt 

0 


curve  in  Fig.  13  for  the  two  maximum 
integral  values,  the  following  formulae  may 
be  used 


Ai+  A2  — 7T  . 


= 7T 


Cl  — Cr 
Cr  — C2 

■“c^ 


= 27T. 
= 27T. 


Xi  — Xr 

Xi 

X,-  — X2 
X2 


(39) 


In  this  case  Xr  and  Cr  are  the  values  of  circuit 
2 at  resonance,  for  which  condition 


J 


00 

i\ . ii  dt  = 0, 
0 


Xi  and  Cl  are  the  values  of  wave  length  and 
capacity  respectively  at  maximum  positive 
deflection  of  the  galvanometer,  while  X2  and  C2 
are  the  corresponding  values  at  maximum 


1214 


GENERAL  ELECTRIC  REVIEW 


negative  deflection  of  the  galvanometer 
(see  Fig.  11).  If  the  extreme  parts  of  the 

00 

i\ . Z2  dt 

0 

curve  are  too  flat  and  the  corresponding 
wave  lengths  and  capacities  can  only  be 
approximately  determined,  the  following  for- 
mulae may  be  used 


where  (7*  and  Cy  are  the  values  for  the 
capacity  and  X*  and  \y  are  the  values  for  the 
wave  length.  All  these  values  correspond  to 
the  intersection  of  the 
00 

ii  . Z2  dt 

0 

curve  with  any  line  parallel  to  the  abscissa, 
such  as  is  shown  in  Fig.  11.  In  this  case  it  is 
convenient  to  plot  the  galvanometer  deflec- 
tions against  the  capacity  or  the  wave  length 
of  the  resonator  circuit. 


APPLICATION  OF  POWER  APPARATUS  TO 
RAILWAY  SIGNALING 

Part  III 
By  H.  M.  Jacobs 

Signal  Accessories  Department,  General  Electric  Company 


This  article  is  the  last  of  a series  of  three  on  the  subject  of  railway  signal  power  apparatus.  The  first,  or 
introductory  article,  described  in  a general  way  the  underlying  principles  of  the  various  systems  in  common 
use,  and  the  second  dealt  only  with  electrically  controlled  signals  for  both  automatic  block  work  along  the 
right-of-way,  and  for  interlockings  at  stations,  terminals,  crossovers,  etc.  The  present  article  describes  a 
few  installations  on  some  of  the  leading  roads  of  the  East  and  Central  West,  dealing  particularly  with  the 
equipment  at  certain  interlocking  towers  that  has  been  put  in  service  within  the  past  three  years. — Editor. 


It  may  be  said  with  a degree  of  certainty 
that  the  sole  thought  in  the  mind  of  the 
average  traveler  relative  to  movements  of 
trains  is  the  desire  to  reach  his  destination 
safelv  and  on  schedule  time ; but  to  a technical 
man,  or  one  interested  in  railroading,  some 
knowledge  about  the  great  organization  of 
trained  workmen  who  devote  their  energies 
to  the  accomplishment  of  these  ends,  and 
of  the  vast  amount  of  equipment  involved, 
adds  interest  to  the  journey. 

The  demand  for  a reduction  in  train 
schedules  and  better  service  has  increased 
tremendously  the  responsibilities  of  the  signal 
department  of  the  various  railroads,  and 
railway  signaling  may  now  be  rightly  con- 
sidered a science  in  itself.  It  is  manifestly 
to  the  advantage  of  any  road  to  establish 
certain  standards,  as  this  will  minimize  the 
amount  of  supplies  to  be  carried  in  its  store- 
houses, and  reduce  the  first  cost  because 
of  the  ability  to  purchase  in  large  quantities 
and  to  duplicate  orders. 

Each  road,  in  solving  its  own  problems, 
has  thus  evolved  its  own  standards,  until  we 
now  have  almost  as  many  standards  as  there 
are  railroads.  The  Railway  Signal  Associa- 
tion, composed  of  men  in  the  employ  of 
signal  departments  of  railroads  and  represent- 


atives of  manufacturers  interested,  was 
formed  to  bring  about  a crystalization  in 
standardization,  to  obtain  an  economical 
and  satisfactory  product,  and  to  establish  a 
certain  excellence  in  manufacture  to  meet  the 
exacting  requirements. 

There  are,  however,  certain  standards  to 
which  the  various  roads  hold  tenaciously ; and 
it  should  be  so,  for  each  is  dependent  on  its 
particular  traffic  requirements,  the  system  of 
signaling  installed,  the  available  power  for 
power-operated  systems,  and  other  elements 
too  numerous  to  mention  here.  It  is  beyond 
the  scope  of  this  article  to  deal  with  signal 
requirements  and  standards;  only  the  power 
equipment  accessory  to  the  operation  of  the 
signal  system  will  be  considered. 

A few  of  the  more  recent  installations  of  the 
past  three  years  are  described  here,  and  in 
addition  the  equipment  for  some  installations 
not  yet  placed  in  service  and  others  installed 
to  handle  a problem  not  encountered  in 
ordinary  power  service. 

NEW  YORK  CENTRAL  86  HUDSON  RIVER 
RAILROAD  CO. 

The  automatic  signals  and  track  circuits 
on  the  New  York  Central  are  operated  from 
storage  batteries  arranged  in  duplicate  groups 


APPLICATION  OF  POWER  APPARATUS  TO  RAILWAY  SIGNALING  1215 


at  each  location  and  so  connected  to  a 
charging  switch  (previously  described)  that 
while  one  group  is  supplying  power  to  the 
signals  the  other  may  be  connected  to  a 
series  charging  line,  in  series 
with  similar  groups  at  other 
locations.  Power  stations, 
located  at  points  where  com- 
mercial power  is  available, 
supply  these  lines  at  a volt- 
age of  from  350  to  600,  as 
conditions  require,  and 
maintain  a constant  cur- 
rent of  5 amperes.  A 
single-panel  switchboard 
controls  the  generator  and 
the  two  feeders,  but  the 
current  in  each  line  is  main- 
tained at  the  proper  charging 
value  by  means  of  series 
plate-type  rheostats.  These 
rheostats  are  mounted  in 
some  instances  on  the  wall 
and  in  others  on  the  back 
of  a separate  panel  which 
also  provides  starting  and 
control  apparatus  for  the 
motor.  The  station  is 
protected  by  choke  coils 
and  Type  ME  lightning 
arresters  on  each  line,  and  the  same  kind 
of  arresters  are  attached  to  the  return  wire 
at  mile  intervals. 

At  the  electric  interlockings  there  are  re- 
quired three  distinct  batteries,  one  floating  on 
the  charging  circuit  and  two  in  duplicate ; the 
main  or  machine  battery  to  deliver  110  to  142 
volts  for  operating  the  signal  and  switch 
motors,  the  lock  and  indicator  batteries  12 
volts,  and  separate  track  batteries  2 volts  for 
supplying  power  to  each  track  circuit  within 
the  limits  of  the  interlocking.  These  batteries 
are  charged  in  series,  or  separately  in  various 
combinations,  from  specially  designed  mer- 
cury arc  rectifiers  having  a high  and  low 
voltage  tube.  The  low  voltage  batteries  alone 
may  be  charged  from  the  high  voltage  tube 
in  series  with  a variable  resistance. 

The  New  York  Central  uses  the  type  of 
switchboard  recently  standardized  by  the 
Railway  Signal  Association  for  charging 
under  the  conditions  just  described,  as  well  as 
the  line  charging  panel  and  the  motor  and  line 
control  panel.  The  rectifier  is  a slight  modifi- 
cation of  the  standard  panel  arranged  to 
obtain  the  double  voltage  range. 

The  most  recent  installation,  shown  in 
Fig.  1,  is  the  interlocking  near  Rome,  N.  Y. 


Directly  back  of  the  motor-generator  set  is 
the  two-way  line  charging  panel  for  the 
signals  on  either  side  of  the  interlocking 
limits.  The  single  feeder  panel  is  for  future 


signaling  over  the  Rome,  Watertown  & 
Ogdensburg  Railroad.  The  rectifier  panel 
stands  at  the  left  of  the  four-panel  board 
adjacent  to  the  motor  and  line  control  panel. 
The  two  interlocking  control  panels  are  at  the 
right. 

Short  interruptions  of  the  power  supply  or 
minor  breakdown  of  part  of  the  charging 
equipment  at  one  of  the  600-volt  line  charging 
stations  causes  little  or  no  concern,  but 
continued  failure  or  destruction  of  the 
station  would  be  a serious  matter.  To  pro- 
vide against  this  emergency  the  railroad  has 
fitted  up  a baggage  car  as  a portable  substa- 
tion. It  contains  a single  cylinder  6-kw., 
600-volt  gasolene-engine-generator  set,  a 600- 
volt  d-c.  to  110-volt  d-c.  motor-generator 
set,  a three-panel  switchboard,  and  complete 
substation  equipment.  The  car  may  be  run 
on  a siding  and  the  charging  line  temporarily 
tied  in. 

BOSTON  86  ALBANY  RAILROAD 

A little  over  a year  and  one-half  ago,  the 
Bostoti  & Albany  put  in  service  an  instal- 
lation of  d-c.  automatic  signals  and  inter- 
locking at  Worcester,  Mass.  The  top  floor 
of  the  signal  tower  contains  the  interlocking 


Fig.  1.  Power  Station,  Electric  Interlocking,  near  Rome,  N.  Y. 
New  York  Central 


1216 


GENERAL  ELECTRIC  REVIEW 


machine,  the  ground  floor  the  five-panel 
switchboard,  power  units  and  relay  rack,  and 
the  basement  the  storage  batteries.  Three- 


Fig.  2.  Railway  Signal  Battery  Charging  Apparatus  Installed 
in  Baggage  Car  for  Emergency  Use.  New  York 
Central  fie  Hudson  River  Railroad 


phase,  60-cycle,  440-volt  power  from  a com- 
mercial source  is  delivered  to  the  switchboard 
for  the  induction  motors  of 
the  two  sets  and  for  a 10- 
kw.,  440/220-volt  single- 
phase step-down  transformer 
that  is  connected  to  a 
mercury  arc  rectifier  for 
charging  the  main  65-cell 
lead-type  storage  battery  for 
the  interlocking  machine. 

The  rectifier  equipment  is 
unique  in  that  it  is  mounted 
on  a 90-inch  three-section 
panel  containing  instruments 
and  switching  equipment  to 
match  the  rest  of  the  switch- 
board. The  interlocking 
battery  is  not  furnished  in 
duplicate  and  must  there- 
fore be  charged  during 
operation.  A fixed  resist- 
ance may  be  cut  into  circuit 
to  draw  from  the  rectifier 
sufficient  current  to  main- 
tain the  arc  on  low  fluctua- 
tions of  load  when  circumstances  require  that 
the  interlocking  machine  be  operated  directly 
from  the  rectifier.  As  it  is  not  advisable  to 


raise  the  voltage  on  the  interlocking  machine  to 
the  high  value  necessary  to  complete  the  battery 
charge,  an  end  cell  switch  has  been  installed. 

One  panel  contains  station  lighting  switches 
and  10  battery  charging  switches  for  the 
track  circuits  within  the  limits  of  the  inter- 
locking. The  local  track  batteries  are  charged 
from  the  rectifier,  and  the  track  and  motor 
batteries  on  either  side  of  the  interlocking  are 
charged  in  series,  similarly  to  the  method  of 
the  New  York  Central  & Hudson  River 
Railroad  previously  described,  from  a 550- 
volt  d-c.  railway  source  controlled  from  a 
switchboard  at  Jamesville,  a few  miles  away. 
The  charging  line  is  carried  through  the  d-p. 
d-t.  lever  switches  on  the  right-hand  panel, 
simply  looping  through  the  station.  In  case 
of  failure  of  this  source  these  switches  may  be 
thrown  down  onto  an  emergency  generator 
circuit,  the  charging  being  controlled  on  this 
panel  by  the  generator  and  two  rheostats, 
one  in  each  line  feeder  extending  in  opposite 
directions  from  the  station.  This  generator 
is  one  unit  of  a three-unit  emergency  set,  the 
other  two  units  being  an  induction  motor  and 
a 110/175-volt  d-c.  generator  to  supplant 
the  rectifier. 

One  panel  controls  the  charging  of  the  dup- 
licate lock  and  indicator  batteries  from  a 
small  two-unit  motor-generator  set  not  shown 
in  Fig.  3. 


Fig.  3.  Power  Equipment  for  Direct  Current  Signaling  Installation  on  the 
Boston  8b  Albany  Railroad,  Worcester,  Mass. 

The  commercial  supply  is  practically  im- 
mune from  a prolonged  failure,  and  as  the 
provision  for  emergency  is  so  complete  and 


APPLICATION  OP  POWER  APPARATUS  TO  RAILWAY  SIGNALING  1217 


the  switching  arrangement  so  flexible,  the 
possibility  of  a total  failure  is  most  remote. 

LAKE  SHORE  & MICHIGAN 
SOUTHERN  RAILWAY 

The  Lake  Shore  & Michigan  Southern 
Railway  recently  placed  in  service  a battery 
charging  equipment  for  the  automatic  inter- 
locking plant  at  Toledo,  Ohio,  the  switchboard 
of  which  is  rather  unique.  Two  mercury  arc 
rectifier  equipments  are  provided,  the  panels 
of  which  match  and  line  up  with  the  switching 
panel,  and  the  switching  arrangement  is  such 


either  separately  or  in  scries  with  cither  the 
main  battery  or  the  portable  batteries;  or 
it  is  possible  to  charge  alone  either  the  track 
batteries,  the  lock  and  indicator  batteries, 
or  a small  number  of  ];ortable  batteries  from 
the  low  voltage  tube  on  one  of  the  rectifiers. 
This  condition  so  seldom  arises  that  it  was 
deemed  unnecessary  to  provide  two  tubes 
on  both  rectifiers.  A six-pole  throw-over 
switch  is  provided  to  interchange  connections 
from  the  high  voltage  to  the  low  voltage 
tube  on  the  rectifier  to  meet  this  special 
condition. 


Fig.  4.  Single-Phase  Mercury  Arc  Rectifier  and  Battery  Feeder  Switchboard  for  Charging  Signal  Batteries,  Lake  Shore 

& Michigan  Southern  Railroad,  Toledo,  Ohio 


that  the  batteries  may  be  charged  in  every 
conceivable  combination. 

The  battery  equipment  consists  of  one  main 
55-cell  interlocking  battery,  two  duplicate 
6-cell  group  track  batteries,  two  duplicate 
10-cell  group  lock  and  indicator  batteries, 
and  a variable  (20  to  90  cells)  Edison  portable 
battery.  Under  normal  conditions  the  port- 
able batteries  will  be  charged  from  one  recti- 
fier and  the  main  battery  from  the  other. 
The  track  batteries  and  lock  and  indicator 
batteries  are  connected  to  d-p.  d-t.  battery 
transfer  switches  in  such  a way  that  the 
discharge  circuits  can  never  be  broken.  The 
batteries  connected  in  the  charging  sides  of 
these  switches  may  be  charged  simultaneously 


The  switchboard  also  provides  four  220-volt 
single-phase  a-c.  lighting  circuits,  each  supply- 
ing a number  of  transformers  having  secon- 
dary taps  to  provide  10,  11,  12,  13,  14  or  15 
volts  for  lighting  the  signals. 

PENNSYLVANIA  RAILROAD  COMPANY 

The  Pennsylvania  Railroad  has  recently 
completed  an  installation  of  automatic  block 
signals  on  the  main  line  between  New  York 
and  Pittsburgh,  and  between  Philadelphia  and 
Washington.  This  comprises  a total  of  895 
track  miles  equipped  with  alternating-  current 
automatic  block  signals,  and  91.2  track  miles 
changed  from  direct-current  to  alternating- 
current  automatic  signals.  Over  this  distance 


1218 


GENERAL  ELECTRIC  REVIEW 


the  signals  are  fed  from  a transmission  line 
supplied  at  intervals  from  the  company’s 
power  plants,  the  spacing  between  plants 
being  determined  approximately  by  the  load 


Fig.  5.  Switchboard  for  Controlling  Two  240-volt  Single-Phase 
Generators  and  Two  3300-volt  Single-Phase  Feeders  for 
Alternating  Current  Signaling  System,  Penn- 
sylvania Railroad 

of  the  intervening  sections  of  the  line.  Each 
station  has  sufficient  capacity  to  feed  in  both 
directions  to  adjacent  stations.  Under  normal 
conditions  each  station  may  be  operated  at 
half-load  feeding  in  one  direction,  or  only 
alternate  stations  may  supply  power  in  both 
directions,  the  other  stations  being  for 
emergency  service.  The  line  is  further 
sectionalized  at  each  signal  location  in  such 
a way  that  should  a short  circuit  occur  the 
faulty  section  may  be  cut  out  and  power  fed 
to  the  remainder  from  the  two  adjacent 
stations,  thus  making  all  signals  operative. 

It  is  important  to  note  a high  degree  of 
standardization  throughout  the  whole  system. 
In  18  stations  the  steam-engine-driven  units 
are  all  35-kv-a.,  220-volt,  single-phase,  60- 
cycle  generators.  The  feeder  panels  with  one 
exception  are  all  arranged  to  feed  in  two 
directions.  Fourteen  stations  have  two 
generating  units  each  with  individual  gener- 
ator control  panels,  four  stations  have  one 
unit  and  generator  panel,  and  one  station  has 
a 25  kv-a.  gasolene-engine-driven  unit  with 
generator  panel  and  one-way  feeder  panel, 
the  equipment  of  all  panels  for  similar  duty 


being  identical.  Fig.  5 illustrates  a two- 
generator,  two-way  feeder  switchboard,  and 
Fig.  6 the  installation  at  the  station  operated 
by  the  gasolene  engine-driven  unit.  In  order 
to  minimize  the  responsibility  of  the  operator 
each  exciter  has  its  own  voltage  regulator, 
so  that  synchronizing  is  simplified  as  much  as 
possible.  The  power  generated  at  220  volts 
is  stepped  up  to  3300  volts  before  going  to  the 
switchboard.  Power  circuits  are  made  and 
broken  on  oil  switches,  and  plug  type  dis- 
connecting switches  are  mounted  on  the 
panels.  All  parts  customarily  exposed, 
whether  low  tension  or  high  tension,  are 
either  completely  covered  by  asbestos  lumber 
cases  or  bushings  securely  clamped,  so  that 
it  is  impossible  for  the  operator  to  come  in 
contact  with  any  live  part,  at  either  front  or 
back  of  board.  When  the  movements  of  the 
semaphore  blades  are  retarded  by  weight  of 
sleet  or  snow,  and  it  is  advisable  to  hasten 
the  movements,  the  line  voltage  is  boosted 
10  per  cent  without  readjustment  of  the 
voltage  regulators  by  opening  a small  lever 


Fig.  6.  Railway  Signal  Power  Station  Installation, 
Pennsylvania  Railroad 

switch  at  the  side  of  the  regulator  base. 
Aluminum  cell  static  dischargers  are  con- 
nected to  the  lines  where  they  leave  the  sta- 
tion. 


APPLICATIONS  OF  POWER  APPARATUS  TO  RAILWAY  SIGNALING  1219 


The  transmission  lines  consist  of  two  No.  4 
or  No.  0 B.&S.  gauge  copper  wires  heavily 
insulated  and  embedded  in  asphaltum  pitch 
in  wooden  trunking  approximately  two  feet 
under  ground.  The  sectionalizing  outfit  at 
each  signal  location  consists  of  an  iron 
mechanism  case  enclosing  a d-p.  d-t.  non- 
automatic oil  switch,  a short-circuit  indicating 
relay,  a 3300/110-volt,  600-watt  or  1000-watt 
transformer,  and  two  primary  plug  cutouts. 
The  transformer  is  connected  to  the  middle 
terminals  of  the  oil  switch,  the  two  throws 
of  which  are  independent,  so  that  when  both 
sides  are  closed  the  transformer  is  connected 
across  the  line  feeding  through;  or  the  trans- 
former may  be  fed  from  either  side  with  the 
other  side  open,  or  cut  off  entirely  by  opening 
both  sides.  The  short-circuit  indicating  relay 
is  connected  in  series  with  the  line  of  the 
normal  power  supply  side,  and  when  actuated 
by  heavy  overload  or  short  circuit  the  arma- 
ture plunger  will  latch  up  and  give  a per- 
manent indication  until  restored  to  normal 
by  an  attendant.  When  a short  circuit  occurs 
in  any  section,  the  relays  in  every  sectionaliz- 
ing outfit  between  the  generating  station  and 
the  faulty  section  will  be  actuated  by  the 
abnormal  current  and  indicate  by  the  position 
of  the  plunger  that  trouble  is  beyond.  An 
attendant  will  then  open  the  outgoing  side 
of  the  oil  switch  in  the  last  sectionalizing  case 


to  the  remainder  of  the  line  from  power 
stations  on  the  two  ends.  It  is  thus  evident 
how  in  a very  short  time  a faulty  section 
may  be  cut  free  with  minimum  interruption 


Fig.  8.  Turbine-Driven  Self-Excited  Alternator, 
Pennsylvania  Railroad 

to  the  system.  The  relays  in  the  outfits 
adjacent  to  an  interlocking  tower  have  their 
auxiliary  contacts  connected  to  an  indicating 
lamp  in  the  tower,  to  assist  in  locating  the 
trouble. 


At  Monmouth  Junction,  N.  J.,  the 
Pennsylvania  Railroad  has  installed 
two  small  steam  turbine-driven 
alternating-current  generators,  5- 
kv-a.,  110-volts,  single-phase  self- 
excited.  A duplicate  set  is  installed 
at  the  North  Philadelphia  station, 
and  a fourth,  similar  in  every  way, 
except  for  operation  on  compressed 
air,  is  in  seWice  at  Rahway,  N.  J. 
These  units  are  only  6 ft.  3 in.  long, 
28^  in.  wide  and  36j^  in.  high. 


CENTRAL  RAILROAD  OF  NEW 
JERSEY 


Fig.  7.  Gasolene  Engine  Set  in  Power  Hous^,  Pennsylvania  Railroad 


giving  the  indication,  and  the  incoming  side 
of  the  oil  switch  in  the  next  adjacent  sectional- 
izing case,  in  order  to  cut  free  the  faulty 
section,  after  which  power  may  be  supplied 


The  accompanying  illustration 
(Fig.  9)  is  typical  of  ten  installa- 
tions on  the  Central  Railroad  of 
New  Jersey  made  during  the  past 
two  years  by  the  Union  Switch  & 
Signal  Company,  and  indicates  the 
standard  for  battery  charging  serv- 
ice for  the  particular  kind  of 
signaling  installed. 

The  motor-generator  sets  (in  duplicate)  are 
arranged  for  d-c. — a-c.  or  a-c. — d-c.  con- 
version, depending  on  the  particular  kind  of 


1220 


GENERAL  ELECTRIC  REVIEW 


commercial  power  available.  The  generators 
are  45-ampere,  20/50-volt  shunt  wound 
machines,  for  charging  Edison  A-0  225- 
ampere-hour  storage  batteries.  The  inter- 


and  discharge  currents  of  both  sets  of  bat- 
teries without  conflict. 

The  more  recent  installation  in  the 
Jersey  City  Terminal  yards  provides  a-c. 
track  circuits  and  lighting  in  towers  “A” 
and  “B,”  while  direct  current  for  charging 
the  interlocking  batteries  is  supplied  from  a 
mercury  arc  rectifier.  Alternating  current  is 
supplied  normally  from  a 575-volt  source 
through  either  one  of  two  duplicate  575/110- 
volt  transformers  and  distributed  to  the 
various  lighting  and  track  circuits.  Emerg- 
ency a-c.  supply  is  available  at  2200  volts. 
This  is  stepped  down  to  575  volts,  and  a 
transfer  equipment  consisting  of  two  double- 
pole contactors  and  a control  relay  provides 
^or  automatically  supplying  power  therefrom 
without  noticeable  interruption  upon  failure 
of  the  normal  source,  and  automatic  resump- 
tion upon  its  return.  All  this  control  equip- 
ment is  mounted  on  a panel  76  in.  high  and 
32  in.  wide.  The  arrangement  in  tower  “C” 
is  somewhat  different.  The  accompanying 
illustration.  Fig.  11,  shows  only  an  a-c. 
feeder  panel  with  transfer  equipment  similar 
to  that  in  towers  “A”  and  “B.” 

CHICAGO,  MILWAUKEE  & ST.  PAUL 
RAILWAY 

The  Chicago,  Milwaukee  & St.  Paul 
Railway  has  recently  put  in  service  the  last 


Fig.  10.  Signal  Tower,  Central  Railroad  of  New  Jersey 

40  miles  of  a 458-mile  alternating-current 
automatic  block  signal  installation,  on  which 
construction  work  was  begun  in  1912.  This 
comprises  five  separate  divisions,  all  double 


Fig.  9.  Battery  Charging  Equipment,  Central 
Railroad  of  New  Jersey 


locking  battery  consists  of  two  duplicate 
groups  of  16  cells  each,  and  the  track  batteries 
of  two  duplicate  groups  of  12  cells  each. 
Each  track  battery  is  subdivided  into  six 
groups  of  two  cells  each,  discharged  in 
multiple  and  charged  in  series.  The  twelve 
groups  of  track  batteries  (six 
on  charge  and  six  on  dis- 
charge) are  so  connected  to 
the  13-blade  charging  switch 
that  the  multiple-series  dis- 
charging groups  are  con- 
nected in  series  to  the 
charging  circuit  and  the 
series  charging  group  in 
multiple-series  to  the  track 
circuit  on  each  throw  of  the 
switch  without  interrupting 
the  track  circuit  supply. 

The  four-pole  double-throw 
transfer  switch  likewise 
interchanges  the  interlock- 
ing batteries  without  inter- 
ruption. The  interlocking 
battery  may  be  charged 
separately  or  in  series  with 
the  charging  group  of  track 
batteries,  and  the  latter  may 
be  charged  separately 
through  small  fixed  resistance  by  a very 
simple  switching  equipment.  By  means  of 
turn  button  type  ammeter  switches  one 
ammeter  serves  to  indicate  both  the  charge 


APPLICATION  OF  POWER  APPARATUS  TO  RAILWAY  SIGNALING  1221 


track,  with  ten  substations,  viz..  Savanna 
to  Elgin,  111.,  having  three  substations;  Lake 
to  Rondout,  one  substation;  Milwaukee  to 
North  La  Crosse,  three  substations;  Bridge 
Switch  to  Hastings,  two  substations;  and 
Minneapolis  to  Hopkins,  one  station.  From 
these  stations  543  automatic  signals  and 
96  semi-automatic  signals  are  supplied. 
All  stations  receive  their  power  from  60- 
cycle  commercial  source,  and  with  one 
exception  all  stations  on  any  one  division 
are  supplied  from  the  same  system  so  that 
the  load  between  stations  may  be  picked 
up  by  either  station  without  interrup- 
tion or  danger  of  interference  between  two 
unsynchronized  power  systems.  Magnetic 
locks  are  provided  on  the  oil  switch  at  the 
Savanna  station  and  on  the  oil  switch 
feeding  to  Savanna  in  the  Forreston  two-cir- 
cuit station,  to  make  connection  between 
these  two  stations  impossible,  as  the  supply 
sources  here  are  two  independent  systems. 

The  panels  are  all  90  in.  high  and  of  natural 
black  slate,  with  the  exception  of  the  station 
at  Sparta,  which  is  blue  Vermont  marble  to 
match  and  line  up  with  an  existing  board. 
Power  is  metered  and  controlled  at  the  voltage 
received.  The  panel  equipment  consists  of  a 
single-phase  watthour  meter,  an  automatic 
oil  switch  with  time-limit  overload  trip  for 
each  feeder,  and  a voltmeter  for  the  bus. 

Transformers  are  located  in  the  outgoing 
feeder  circuits  to  step-up  from  the  receiving 
voltage  to  4400  volts  for  transmission.  A 
spare  transformer,  equal  in  capacity  to  that 
of  the  heaviest  feeder,  is  installed  in  each 
station,  together  with  primary  and  secondary 
switching  equipment. 

The  stations  on  the  ends  of  the  section  are 
single  feeder,  and  the  intermediate  stations 
double  feeder,  and  of  such  capacity  that  the 
total  load  may  be  carried  by  alternate  stations 
if  desired.  Emergency  operation  is  thus 
provided  under  all  conditions,  in  a manner 
similar  to  that  on  the  Pennsylvania  Railroad 
already  described. 

With  the  exception  of  the  Portage  station, 
the  eommercial  power  supply  seldom,  if  ever, 
fails.  In  order  to  guard  against  rather 
frequent  interruption  at  the  Portage  plant, 
an  auxiliary  equipment  has  been  furnished, 
which  consists  of  a two-unit  motor-generator 
set,  the  motor  being  of  the  synchronous  type 
driving  an  a-c.  generator  to  charge  a 90-cell 
Edison  storage  battery.  The  switchboard 
and  set  are  furnished  with  such  automatic 
control  equipment  that  upon  failure  of  the 
a-c.  power  supply,  the  set  will  run  from  th6 


storage  battery,  supplying  the  signal  line 
from  the  a-c.  machine  at  normal  voltage  and 
frequency  without  interruption.  A synchro- 
nizing equipment  is  provided  so  that  upon 
resumption  of  the  commercial  supply  the 
a-c.  machine  may  be  synchronized  and 
operation  resumed  as  before.  This  equipment 
has  been  in  satisfactory  operation  for  over 
nine  months. 

The  Chicago,  Milwaukee  & St.  Paul  Rail- 
way is  particularly  fortunate  in  having  ample 
and  satisfactory  commercial  power  available 
and  has  carried  out  the  idea  of  standardizing 
power  apparatus  to  a very  high  degree. 

NEW  YORK,  NEW  HAVEN  8e  HARTFORD 
RAILROAD 

Directly  across  the  tracks  from  the  Boston 
& Albany  installation  described  is  the  inter- 
locking tower  and  power  plant  controlling 
the  alternating-current  signals  and  inter- 
locking on  the  New  York,  New  Haven  & 
Hartford  Railroad.  The  tower  is  of  pleasing 
architectural  design,  is  of  concrete  construc- 
tion and  three  stories  high.  The  upper  story 
contains  the  interlocking  machine,  the  ground 
floor  the  switchboard  duplicate  power  units 
and  relay  racks,  and  the  basement  the  storage 
batteries  and  transformers  for  the  incoming 
line. 

The  switchboard  consists  of  two  induction 
motor  panels,  two  d-c.  panels,  a storage  bat- 
tery panel,  two  a-c.  generator  panels,  and  the 
synchronizing  and  speed  regulator  equipment. 
The  three  units  comprising  the  duplicate 
motor-generator  sets  are  a three-phase,  60- 
cycle,  440-volt  induction  motor,  a 7^-kv-a., 
single-phase,  60-cycle,  440-volt  self-excited 
alternating-current  generator,  and  a 10-h.p., 
90/160-volt  shunt  wound  d-c.  machine.  Only 
one  set  is  in  operation  at  a time,  the  other 
being  held  in  reserve. 

Under  normal  conditions  the  motor  sup- 
plied from  the  commercial  power  source  drives 
the  set,  the  signal  circuits  being  supplied 
from  the  a-c.  generator,  while  the  d-c. 
machine  either  charges  or  floats  on  the 
storage  battery.  Upon  failure  of  the  com- 
mercial power  supply  the  d-c.  machine  auto- 
matically acts  as  the  motor  of  the  set, 
operating  from  the  storage  battery.  Speed  is 
held  constant  by  an  automatic  speed  regu- 
lator. The  battery  has  capacity  sufficient  to 
thus  operate  the  system  one-hour.  Upon 
resumption  of  power,  it  is  unnecessary  to 
synchronize  the  motor,  as  it  is  of  the  induction 
type. 


1222 


GENERAL  ELECTRIC  REVIEW 


DELAWARE,  LACKAWANNA  8t 
WESTERN  RAILROAD 

A little  less  than  two  years  ago,  the  Dela- 
ware, Lackawanna  & Western  Railroad  put 
in  service  an  electro-pneumatic  interlocking 
plant  at  Montclair,  N.  J.  The  power  plant 


of  main  battery  are  so  connected  that,  when 
interchanging  them  from  charge  to  discharge 
and  vice  versa,  the  discharge  circuit  is  never 
interrupted.  The  track  batteries  are  so  con- 
nected to  a five-pole  double-throw  switch  that 
the  two  component  groups  of  the  charging  set 


Fig.  11.  ‘‘The  Yankee**  passing  Signal  Tower  at  Worcester,  Mass.  N.  Y.,  N.  H.,  fls  H.  R.R. 


shown  in  the  illustration  is  located  in  the 
basement  of  the  signal  tower  and  consists 
of  two  duplicate  induction  motor-driven  air 
compressors,  duplicate  sets  of  Edison  A- 10 
batteries  for  the  interlocking  and  for  track 
circuits,  three  motor-gener- 
ator sets  for  battery 
charging,  and  a switchboard 
to  control  all. 

The  air  compressors  are 
each  of  100  cu.  ft.  per  minute 
capacity  and  of  the  four- 
cylinder  two-stage  type,  and 
are  driven  through  double- 
herringbone gears  by  three- 
phase,  60-cycle,  ISOO-r.p.m. 
induction  motors  starting 
on  external  resistance  in  the 
rotor  circuit  and  controlled 
from  the  switchboard. 

The  motor-generator  sets 
are  of  unit  frame  construc- 
tion. The  motors  are  three- 
phase  60-cycle,  220-volt 
machines,  and  the  shunt 
wound  generators  are  rated 
for  75  amperes,  15  volts. 

The  main  batteries  for  the 
interlocking  are  arranged 
in  two  duplicate  sets  of  16  cells  each, 
and  the  track  batteries  in  duplicate  sets  of 
two  groups,  four  cells  per  group,  or  a total 
of  eight  cells  per  set.  The  two  duplicate  sets 


are  in  series  and  those  of  the  discharging  set  in 
multiple ; and  by  reversing  the  position  of  the 
switch  the  duty  of  the  two  sets  of  batteries, 
as  well  as  the  connections,  are  interchanged 
without  disturbance  to  the  discharge  line. 


Fig.  12.  Power  Equipment  for  Alternating  Current  Signaling  Installation  on 
New  York,  New  Haven  & Hartford  Railroad,  Worcester,  Mass. 


The  switchboard  is  so  arranged  that,  by 
running  all  three  motor-generator  sets  at  the 
same  time,  the  track  batteries  may  be 
charged  from  any  one,  and  the  main  battery 


APPLICATION  OF  POWER  APPARATUS  TO  RAILWAY  SIGNALING 


1 223 


from  the  other  two  connected  in  series;  but 
should  any  one  set  be  disabled  the  main 
battery  may  be  charged  from  the  remaining 
two,  and  when  the  charge  is  coni]3lete  the 
track  batteries  may  be  charged  from  either 
one  of  these.  Thus  by  alternating  the  times 
of  charge  the  two  sets  of  batteries  may  be 
charged  one  at  a time  from  the  two  motor- 
generator  sets,  so  that  the  disability  of  the 
other  set  will  not  cripple  the  system. 

With  the  exception  of  the  air  compressor 
governor,  which  is  located  on  the  wall,  the 
automatic  starting  equipment  is  all  mounted 
on  the  switchboard.  The  air  governor  is  set 
for  operation  between  SO  and  90  pounds  per 
square  inch.  A six-pole  double-throw  lever 
switch  connects  one  or  the  other  of  the 
compressors  to  the  operating  circuits. 

LONG  ISLAND  RAILROAD 

The  recent  electro-pneumatic  a-c.  signal 
installation  on  the  Long  Island  Railroad  at 
Jamaica,  N.  Y.,  requires  four  separate 
interlocking  towers,  all  of  which  receive  a-c. 
power  at  2200  volts,  25  cycles,  which  is 
transformed  to  220  volts  for  delivery  to  the 
switchboard.  The  compressed  air  for  operat- 
ing the  switches  and  signals  is  obtained  from 
the  company’s  car  shops  at  Morris  Park,  near 
tower  “ R.” 


Both  steam  and  electric  trains  pass  through 
the  interlocking,  but  by  far  the  greater 
number  are  electric,  as  the  lines  to  New  York 
and  Brooklyn  are  electrified.  500-volt  d-c. 


propulsion  current  is  supplied  from  the 
insulated  third  rail. 

In  each  of  the  two  small  towers,  “R”  and 
“MP,”  the  motor-generator  set  for  charging 
the  duplicate  7-cell  lead  type  interlocking 
battery  consists  of  a 220-volt,  single-phase, 
25-cycle  induction  motor  and  a 25-volt, 
25-ampere  shunt  wound  d-c.  generator.  The 
switchboard  distributes  at  220  volts  single- 
phase to  the  induction  motor  and  to  the  track 
circuits,  and  from  the  latter  further  trans- 
formation is  made  at  each  track  section  to  a 
lower  voltage.  It  also  supplies  one  of  two 
duplicate  transformers  for  the  signal  lighting 
circuits  through  the  upper  contacts  of  a 
relay  held  in  by  energy  from  the  a-c.  circuit. 
Upon  failure  of  the  a-c.  supply  this  relay 
connects  the  lighting  circuits  to  the  d-c. 
storage  battery. 

At  each  of  the  two  larger  towers  “J”  and 
“JE”  the  switchboard  distributes  at  220 
volts  single-phase  to  the  motor,  track  circuits 
and  lights.  On  account  of  the  more  extensive 
distribution  of  the  lighting  feeders,  it  is  not 
feasible  to  supply  them  at  low  voltage  as  from 
the  two  smaller  towers.  To  provide  the 

feature  of  having  emergency  power  available 
for  the  lighting  circuits  when  desired,  the 
motor  of  the  set  is  made  of  the  synchronous 
type,  excited  from  the  d-c.  machine,  and  upon 
failure  of  the  a-c.  supply  the 
d-c.  machine  will  run  as  a 
motor  from  the  storage  bat- 
tery and  the  a-c.  machine  as 
a single-phase  generator, 
supplying  only  the  lighting 
circuits.  To  govern  this 

emergency  action  a master 
relay  energized  from  the  a-c. 
source  having  upper  and 
lower  contacts,  an  auto- 
matic starting  equipment 
and  two  field  rheostats  for 
the  d-c.  machine,  are  re- 
quired. The  connections  to 
the  two  rheostats,  are  inter- 
changed by  the  master  relay, 
one  rheostat  being  in  circuit 
when  the  machine  is  gener- 
ating and  the  other — for 
governing  the  speed  of  the 
set — when  motoring. 

The  control  circuits  are 
so  connected  through  the 
relay  contacts  ^and  a third  blade  of  the 
lighting  switches  that  should  the  a-c.  power 
fail  in  the  daytime,  when  the  two  light- 
ing switches  are  open,  the  set  will  come 


Fig.  12a  Power  Station  in  Electro-Pneumatic  Interlocking  Tower, 
Delaware,  Lackawanna  6a  Western  Railroad 


1224 


GENERAL  ELECTRIC  REVIEW 


to  a standstill  if  charging  the  batteries,  or 
remain  at  a standstill  if  in  this  condition. 
When  the  lighting  switches  are  closed,  the  set, 
if  charging  the  battery,  will  continue  to  run 


Fig.  13.  “JE”  Tower,  Long  Island  R.R.,  Jamaica,  N.  Y. 


from  the  battery;  but,  if  the  set  is  at  a 
standstill,  the  automatic  starting  equipment 
will  immediately  become  active  and  start 
the  set,  throwing  power  on  the  lighting  cir- 
cuits from  the  a-c.  machine  within  a very 
few  seconds. 

The  automatic  equipment  is  arranged  so 
that  upon  reversal  of  the  set  the  lighting 
circuits  are  cut  free  from  the  220-volt  bus, 
otherwise  the  set  would  become  overloaded 
and  pump  back  on  the  supply  line.  A switch 
is  provided  in  the  starting  control  circuit  so 
that  the  set  may  be  started  at  any  time 
desired. 

The  switchboards  and  sets  in  the  two  larger 
towers  are  exactly  the  same  in  design  and 
arrangement,  the  only  difference  being  in 
capacity  of  equipment,  to  provide  in  one  a 
normal  charging  rate  of  40  amperes  and 
in  the  other  60  amperes. 

SOUTHERN  RAILWAY 

The  General  Railway  Signal  Company  have 
now  under  construction  four  signal  instal- 
lations on  the  Southern  Railway  which 
require  seven  substations  and  two  power 
stations.  Four  of  the  substations ; Lynchburg, 
Va.,  Morristown,  Tenn.,  Howell  and  Gaines- 
ville, Ga.,  are  exact  duplicates,  receiving  the 
power  from  commercial  sources  at  2200  volts, 
three-phase,  60-cycle  and  delivering  30  kv-a. 
at  4400  volts,  three-phase.  The  substation  at 
Coster,  Tenn.,  receives  power  at  220  volts 
and  delivers  30-kv-a.  at  4400  volts,  three- 


phase,  60-cycle.  The  two  remaining  sub- 
stations are  “outdoor  type,”  that  is,  a steel 
switch  house  is  located  at  the  foot  of  a pole 
structure  supporting  the  transmission  line 
and  houses  the  switchboard,  instruments, 
meters  and  instrument  transformers.  The 
power  transformers,  disconnecting  switches, 
choke  coils  and  lightning  arresters  are  sup- 
ported on  the  pole  structure.  The  power 
houses  at  Monroe  and  Whittles,  Va.,  are 
exact  duplicates  except  in  capacity. 

In  these  nine  stations  standardization  has 
been  strenuously  adhered  to.  One  power 
station  has  a capacity  of  50  kv-a.,  three-phase, 
and  the  other  power  station  and  six  sub- 
stations 30-kv-a.,  three-phase;  the  remaining 
substation,  connected  temporarily  single- 
phase, will  ultimately  be  the  same. 

All  stations  bear  a similarity  in  layout  and 
arrangement  of  apparatus.  Disconnecting 
switches  are  provided  at  the  low  tension  side 
of  power  transformers  and  at  the  line  side 
of  the  high  tension  apparatus.  The  automatic 
oil  switch,  ground  detector,  current  and 
potential  transformers  for  the  meter  instru- 
ments, inverse  time-limit  overload  relay, 
choke  coils  and  lightning  arresters  are 
connected  in  the  4400-volt  circuit  in  the 
order  given.  One  potential  transformer  is 
between  the  power  transformer  and  the  oil 
switch  to  indicate  whether  power  is  available 
from  the  supply. 

The  switchboards  of  the  four  duplicate 
substations  consist  of  two  panels  90  in.  high, 
each  of  two  sections  of  natural  black  slate 
mounted  on  pipe  supports  and  surmounted 
by  the  ground  detector.  Two  incandescent 
lamps  in  goose  neck  brackets  afford  ample 
illumination  for  the  horizontal  edgewise 
instruments  directly  beneath.  Current  may 
be  read  in  any  phase  on  the  one  ammeter 
by  a three-way  ammeter  switch,  and  a short- 
circuiting  switch  is  provided  to  protect  the 
instrument  against  the  heavy  starting  load. 
Switches  are  provided  for  station  lighting. 
The  watthour  meter  is  mounted  on  the  sub- 
base. 

The  two  power  house  switchboards  each 
consist  of  three  panels  similar  in  height  of 
sections,  material  and  mounting  to  the  four 
substation  switchboards.  The  high  tension 
feeder  equipment  and  its  comparative  arrange- 
ment in  the  circuit  is  identical  with  that 
in  the  substation  feeders.  As  the  generator 
voltage  is  220,  the  triple-pole  fused  main 
switch  acts  as  a disconnecting  switch  for  the 
low  tension  side  of  the  power  transformer. 
A voltage  regulator  and  the  customary  equip- 


APPLICATION  OF  POWER  APPARATUS  TO  RAILWAY  SIGNALING  1225 


ment  for  controlling  the  generator  and  its 
exciter  are  provided. 

The  substation  switchboard  at  the  Coster 
power  house  consists  of  two  panels  90  in. 
high,  each  of  three  sections  of  blue  Vermont 
marble  mounted  on  angle  iron  supports  to 
match  and  line  up  with  the  existing  power 
switchboard.  The  equipment  is  identical  with 
the  two  power-house  switchboards,  except  for 
the  omission  of  the  regulator  and  panel, 
rheostat  handwheel,  exciter  switch  and  exciter 
instruments,  with  the  consequent  reduction 
in  width  of  the  low  tension  panel. 


Fig.  14.  Front  View  of  Outdoor  Substation,  Three-Phase, 
4400-Volt  Railway  Signal  Line,  Southern  Railway 


key  socket  provides  ample  light  for  reading 
instruments. 

SIGNALING  ON  INTERURBAN  LINES 

Hand-controlled  lamp  signals  for  turnouts 
and  sidings  and  stretches  of  single  track  have 
been  in  use  for  some  time,  as  well  as  the 
automatic  permissive  signals  so  common 
on  single  track  portions  of  the  city  lines  which 
permit  movement  of  any  number  of  cars 
in  only  one  direction  until  the  section  is  clear 
before  allowing  a movement  in  the  opposite 


Fig.  15.  Back  View  of  Outdoor  Substation 
shown  in  Fig.  14 


Figs.  14  and  15  show  front  and  rear  views  of 
the  first  outdoor  type  substation  of  this  par- 
ticular class  for  railway  signal  purposes.  Two 
of  these  stations  are  to  be  installed,  one  at 
Inman,  S.  C.,  and  the  other  at  Austell,  Ga. 
They  are  duplicates  except  that  the  latter  is 
temporarily  connected  single-phase,  although 
the  full  three-phase  equipment  is  furnished  so 
that  it  may  be  made  three-phase  in  a few 
moments  by  slight  changes  in  the  instrument 
transformer  secondary  circuits.  The  equip- 
ment is  the  same  as  that  for  the  other  sub- 
stations, except  that  no  provision  is  made 
for  reading  current.  The  instrument  trans- 
formers and  high  tension  connections  are 
clearly  shown  in  the  back  view.  A lamp  with 


direction.  These,  however,  place  no  restriction 
on  the  spacing  between  cars  and  give  no 
indication  as  to  the  condition  of  the  track 
ahead. 

Interurban  service  is  akin  to  railroad 
service  in  that  it  requires  heavier  rolling 
stock,  increased  speed  and  a definite  time 
sehedule  to  be  maintained  under  all  condi- 
tions of  weather.  Such  rapid  strides  have 
been  made  in  the  development  of  inter- 
urban equipment  in  the  past  few  years  that 
automatic  block  signaling  has  become  not 
only  a refinement,  but  a necessity. 

The  latter  half  of  the  year  1913,  saw  a great 
many  extensive  signal  installations  on  inter- 
urban roads,  notably  the  lines  in  Ohio, 


1226 


GENERAL  ELECTRIC  REVIEW 


Indiana  and  Illinois,  on  the  Scranton  & 
Binghamton  line  in  Pennsylvania,  and  on  the 
New  York  State  Railways  near  Rochester 
and  Syracuse. 

In  nearly  every  instance  the  switchboards, 
power  transformers  and  switching  equipment 
are  installed  in  the  same  substation  with  the 
rotary  converters  that  supply  the  motive 
power.  Power  is  taken  from  the  mains 
supplying  the  rotary  converters  (usually 
370  volts,  25  cycles)  and  stepped  up  through 
duplicate  transformers  to  2200  volts  for 
distribution  to  the  2200/110-volt  trans- 
formers supplying  the  block  sections.  In  some 
instances  the  transmission  voltage  is  4400. 

In  most  cases  the  switchboards  are  90  in. 
high  and  of  two  or  three  sections,  slate  or 
marble,  to  match  the  existing  switchboard. 
Where  unnecessary  to  line  up  with  existing 
boards,  48  in.  panels  on  76  in.  supports  are 
usually  furnished.  The  controlling  equipment 
for  a two-circuit-feeder  panel  usually  consists 
of  two  fused  lever  switches  supplying  the 
step-up  transformers,  two  oil  switches  with 
inverse  time-limit  overload  relays  and  alarm 
bell  attachment,  two  current  transformers  and 
ammeters  with  an  illuminating  lamp,  and  an 
alarm  bell  to  give  notice  of  an  open  oil 
switch. 

Boards  installed  at  the  end  of  the  signaled 
territory  are  only  single-circuit,  but  in  those 
cases  where  the  signaling  will  be  extended  at 
some  future  time  the  boards  in  many  instances 
have  been  made  of  ample  size  to  contain  the 
equipment  for  two  circuits,  although  equip- 
ment for  only  one  circuit  is  furnished. 

On  many  switchboards  that  have  the 
ammeter  connected  in  the  supply  side  of  the 
step-up  transformer,  it  has  been  necessary 
to  furnish  a switch  to  short  circuit  the 
ammeter  on  energizing  the  line  because  of  the 
heavy  momentary  rush  which  sometimes 
occurs  when  connecting  the  transformer — 
particularly  a low  frequency  transformer — 
to  the  supply  line  under  load.  To  eliminate 
this  trouble  and  get  away  from  an  oil  switch 
which  has  a rupturing  capacity  far  in  excess 
of  what  is  required  on  such  low  capacity 
circuits  a switchboard  has  been  developed  and 
built  for  the  Union  Switch  & Signal  Company, 
for  an  installation  on  the  Scranton  & Bing- 
hamton road.  The  double-pole  circuit  breaker 
in  the  low  tension  side  furnishes  ample  overload 
protection,  and  ordinary  outdoor  type  plug 
cutouts  guard  against  possible  trouble  from 
the  outside.  The  low  tension  sides  of  the 
duplicate  transformers  are  connected  to  the 
d-p.  d-t.  lever  switch  and  the  high  tension 


sides  to  the  plug  switches  and  only  one  pair 
of  plugs  furnished,  so  that  the  inactive 
transformer  will  be  dead.  For  two  circuits 
either  duplicate  panels  or  a panel  with  double 
this  equipment  would  be  furnished. 

NEW  YORK,  WESTCHESTER  fis 
BOSTON  RAILWAY 

The  New  York,  Westchester  & Boston 
Railway,  connecting  White  Plains  and  New 
Rochelle  with  New  York  City,  is  the  only 
strictly  suburban  electric  railroad  built  from 
the  ground  up  without  an  old  road  bed  as  a 
basis.  It  consists  of  a four-track  section 
approximately  seven  miles  in  length  con- 
necting with  the  four  main  tracks  of  the 
Harlem  River  branch  of  the  New  York, 
New  Haven  & Hartford  Railroad  system  near 
174th  Street,  New  York  City,  and  extending 
northward  to  Columbus  Avenue,  Mount 
Vernon,  where  it  separates  into  two  double- 
track lines,  one  continuing  northward  to 
White  Plains,  9.4  miles,  and  the  other 
eastward  to  New  Rochelle,  2 miles,  where 
it  again  connects  with  the  New  Haven 
system. 

Transportation  systems  in  New  York  City 
are  universally  direct-current  furnished  by 
substations ; this  road,  however,  from  its 
connections  with  the  New  Haven  system  and 
the  successful  operation  of  the  installation 
there  existing,  naturally  installed  the  same 
system.  Power  is  purchased  from  the  New 
Haven  power  house  at  Cos  Cob,  Conn.,  the 
connection  being  made  at  the  end  of  the 
New  Rochelle  branch  sixteen  miles  distant. 
The  transmission  is  three-phase,  11,000  volts, 
the  conductors  being  carried  on  the  extended 
posts  of  the  steel  compound  catenary  struc- 
tures. Though  only  one  phase  is  used  for 
propulsion,  the  three-phase  circuit  is  carried 
from  the  point  of  supply  to  the  machine 
shops,  elevator  motors,  pumps,  and  substation 
for  the  signal  system. 

On  steam  roads  either  direct-  or  alternating- 
current  signal  circuits  may  be  selected;  on 
roads  having  direct-current  for  propulsion 
using  both  rails  for  both  propulsion  and 
signal  current,  the  latter  must  be  alternating; 
but  on  roads  using  alternating-current  for 
bdth  propulsion  and  signaling,  employing  both 
rails  for  both  circuits,  the  frequency  of  the 
latter  must  not  be  a low  harmonic  of  the 
former.  This  is  necessary  because  of  the 
fact  that  the  signal  relays  must  be  selective 
as  to  frequency.  Suppose  the  propulsion 
current  to  be  25-cycle  and  the  signal  current 


APPLICATION  OF  POWER  APPARATUS  TO  RAILWAY  SIGNALING 


1227 


60-cycle,  each  supplied  from  a different 
source.  Now  if  the  former  should  rise  to  30 
cycles,  or  the  latter  drop  to  50  cycles,  the 
frequency  of  the  signal  circuits  would  be  just 
twice  that  of  the  propulsion 
circuit  and  serious  trouble 
result  from  false  signal  indi- 
eations.  To  obviate  such 
difficulties  and  maintain  a 
certain  fixed  ratio  between 
the  frequencies  of  the  two 
circuits,  a motor-generator 
set  supplied  from  the  same 
source  is  necessary. 

Ordinary  fiber-insulated 
rail  joints  at  the  ends  of  the 
blocks  serve  to  isolate  the 
track  circuits  in  each  block; 
but  to  permit  the  con- 
tinuous flow  of  the  return 
propulsion  current  imped- 
ance bonds  are  installed  in 
pairs  at  eaeh  block  end 
across  the  two  rails,  one  on 
each  side  of  the  insulated 
joints.  These  are  coils 
wound  on  an  iron  core,  with 
the  middle  taps  of  the  coils  of  each  pair 
connected  together.  They  are  enelosed 
in  an  iron  case  mounted  between  the 
rails  with  the  top  practically  flush  with  the 
surface  of  the  ballast.  An  installation  is  shown 
in  Fig.  8 of  the  first  article  of  this  series 


Fig.  16.  Exterior  of  New  York,  Westchester  6c  Boston  Rwy. 
Signal  Substation,  Columbus  Ave., 

Mt.  Vernon,  N.  Y. 

(December,  1913).  The  propulsion  current 
passes  into  both  ends  of  one  bond,  through 
the  common  wire,  and  into  the  two  rails  of  the 
other  block  through  the  two  ends  of  the 


other  bond ; and  thus,  by  setting  up  neutraliz- 
ing magnetic  fields  in  each  bond,  passes  across 
the  block  section  with  a negligible  energy  loss. 
As  the  signal  current  flows  in  opposite  direc- 


Interior View  of  Signal  Substation  shown  in  Fig.  16 

tions  in  the  two  rails,  it  flows  through  the  bond 
from  end  to  end,  and  as  the  bond  is  highly 
inductive,  a choking  effect  is  introduced 
which  permits  only  a negligible  portion  to  pass 
through,  shunting  practically  all  the  track 
circuit  current  through  the  track  relays. 

The  signal  substation  at  Columbus  Avenue, 
Mount  Vernon,  is  a brick  structure  of  one  story, 
with  a high  tension  gallery  at  one  end  for  the 
entrance  of  the  two  three-phase,  11,000-volt 
duplicate  lines.  Only  four  wires  are  brought 
into  the  building,  as  the  completing  wire  for 
each  set  of  lines  eomes  from  the  grounded 
tracks.  The  gallery  contains  the  high  tension 
multigap  lightning  arresters,  disconnecting 
switches,  choke  coils,  a d-p.  d-t.  disconnecting 
switch  for  selecting  operation  between  the  two 
pair  of  lines,  high  tension  series  inverse 
time-limit,  overload  relays  for  tripping  the 
two  main  oil  switches  downstairs,  and  high 
tension  instrument  transformers,  all  insulated 
to  stand  a surge  potential  of  30,000  volts. 
Surges  are  frequently  set  up  by  disturbances 
on  the  propulsion  circuit  and  the  phases  are 
badly  unbalanced  because  the  voltage  regu- 
lators on  the  Cos  Cob  generators  regulate  on 
the  “propulsion”  phase,  which  necessarily 
fluctuates  greatly. 

The  ground  floor  of  the  substation  is 
divided  into  three  parts,  viz.,  the  high  voltage 
section  directly  under  the  gallery  containing 


1228 


GENERAL  ELECTRIC  REVIEW 


the  two  line  switches  and  duplicate  banks  of 
step-down  transformers,  the  operating  room, 
containing  the  switchboard  and  duplicate 
motor-generator  sets,  and  the  battery  room. 

From  the  disconnecting  switch  in  the 
gallery  selecting  between  the  two  incoming 
lines,  all  the  apparatus  is  in  duplicate.  One 
complete  equipment  consists  of  a small  panel 
for  a d-p.  s-t.  oil  switch  (double-pole  because 
one  leg  of  the  three-phase  circuit  is  grounded) ; 
three  delta-connected  transformers  stepping 
down  from  11,000  to  440  volts;  a four-unit 
motor-generator  set  consisting  of  75-h.p., 
Form  K induction  motor,  a 10-pole,  37-kv-a., 
2200-volt,  60-cycle  single-phase  alternating- 
current  generator  with  3-kw.,  125-volt  exci- 
ter, and  a direct  current  machine  to  operate 
between  110  and  160  volts  as  a generator  to 
charge  the  storage  battery,  and  110  to  90 
volts  as  a 75-h.p.  motor;  and  controlling  equip- 
ment for  each  machine  on  the  switchboard. 
One  set  is  of  sufficient  capacity  to  take  care 
of  the  probable  ultimate  requirements  of  the 
road,  so  that  the  other  may  be  always  kept 
as  a spare. 

Under  normal  conditions  the  d-c.  machine 
is  either  charging  or  floating  on  the  battery. 
Upon  failure  of  the  power  supply,  the  low 
voltage  trip  attachment  opens  the  main  line 
oil  switch,  cutting  off  the  induction  motor, 
whereupon  the  d-c.  machine  acts  as  the  motor 
of  the  set.  The  speed  regulator  on  the  d-c. 
machine  and  the  voltage  regulator  on  the 
a-c.  machine  are  so  nicely  adjusted  that  a 
failure  and  subsequent  resumption  of  supply 
power  produces  no  noticeable  effect  on  the 
signal  supply.  Upon  resumption  of  power  the 
operator  closes  the  main  line  switch  (it  being 
unnecessary  to  synchronize  as  the  motor  is 
of  the  induction  type),  and  the  operation  is 
resumed,  the  d-c.  machine  charging  at  a 
greater  rate  because  of  the  depleted  condition 
of  the  battery. 

The  switchboard  consists  of  d-c.  generator- 
motor  panel,  induction  motor  panel,  and  a-c. 
generator  panel,  each  in  duplicate,  and  the 
three  twin-circuit  feeder  panels.  The  d-c. 
panels  each  have  a starting  switch  for  starting 
the  set  from  the  storage  battery,  although 


it  is  usually  started  from  half  voltage  taps 
on  the  transformers  through  double-pole, 
double-throw  lever  switch  on  the  motor 
panel.  The  d-c.  panels  also  have  circuit 
breaker,  double  reading  ammeter,  line  switch 
and  rheostat  handwheel  for  regulating  the 
charging.  On  the  back  of  each  panel  is 
another  rheostat  that  is  cut  into  circuit  by 
the  speed  regulator  when  the  d-c.  machine 
is  motoring,  but  this  is  set  to  maintain  proper 
speed  under  full  load. 

The  battery  is  of  sufficient  capacity  to  drive 
the  set  under  full  load  for  25  minutes,  begin- 
ning with  a full  charge,  before  the  voltage 
falls  to  90.  When  it  reaches  this  value  a circuit 
breaker  located  on  the  back  of  the  board 
and  calibrated  to  trip  out  at  90  volts,  or 
under,  will  open  the  circuit  in  order  to  save 
the  battery  from  destruction.  This  pre- 
caution is  hardly  necessary,  for  failures  have 
been  at  most  only  of  few  minutes’  duration. 

The  generator  panels  also  provide  exciter 
control,  and  the  speed  regulator  relays  and 
contactor  equipment  are  mounted  on  the 
subbases.  The  three  feeder  panels  feed  in  all 
three  directions  from  the  junction  point,  each 
supplying  twin  single-phase  lines  through  a 
d-p.  d-t.  oil  switch  having  a common  trip  coil. 
The  duplicate  signal  mains  carried  on  the 
extended  posts  of  the  catenary  bridges  supply 
step-down  transformers  for  the  signals  and 
track  circuits.  The  lines  are  run  in  pairs  so 
that  should  one  become  grounded  or  defective, 
or  require  repairs  at  any  point,  that  portion 
between  the  two  adjacent  sectionalizing 
outfits  may  be  cut  out  and  operation  con- 
tinued through  the  other. 

The  seven  interlocking  plants  are  all  built 
along  similar  lines.  Direct  current  for 
operating  the  switches  and  interlocking  func- 
tions is  furnished  from  a 110-volt  storage 
battery.  The  switchboard.  Fig.  17,  taking 
power  at  110  volts,  60-cycle,  single-phase 
from  duplicate  transformers  supplied  from 
the  signal  transmission  line  for  furnishing 
power  to  the  track  circuits  and  lights  on 
either  side  of  the  tower  controls  the  small 
motor-generator  set  for  charging  the  battery 
by  continuous  floating. 


FROM  THE  CONSULTING  ENGINEERING  DEPARTMENT  OF  THE 
GENERAL  ELECTRIC  COMPANY 


1229 


FAULTY-FEEDER  LOCALIZER 


This  panel  carries  on  its  front  the  indicating 
lights  and  also  the  switches  necessary  for 
retaining  the  balanced  condition  of  the 
relays  under  different  operating  conditions. 
This  balancing  operation  is  very  simple.  If 
a feeder  is  in  service  its  corresponding  relay 
switch  is  placed  in  the  upper  position.  If 
the  feeder  is  out  of  service  the  relay  switch  is 
thrown  down. 


In  the  operation  of  a high-tension  electrical 
system,  it  frequently  happens  that  a single 
wire  arcs  to  ground.  This  arc  may  be  caused 
by  lightning,  weak  insulation,  or  some 
remote  disturbance  on  the  system.  Unless 
this  arc  is  extinguished  it  will  very  quickly 
cause  considerable  damage  such  as  burning 
off  the  wire,  breaking  an  insulator, 
or  arcing  to  the  other  phase  wires, 
thus  causing  a short  circuit  (a  non- 
grounded  neutral  system  is  here  as- 
sumed). It  is  the  function  of 
the  arcing-ground  suppressor  to 
promptly  extinguish  this  arc  be- 
fore damage  results. 

Suppose  the  fault  to  be  of  per- 
manent nature.  If  there  are  a num- 
ber of  feeders  connected  to  the  bus 
there  is  no  way  of  telling  on  which 
one  the  arc  has  occurred.  The 
faulty-feeder  localizer  is  designed 
to  select  the  faulty  feeder  and  light 
the  corresponding  indicating  lamp, 
thus  giving  this  important  infor- 
mation to  the  station  operator. 

With  this  knowledge  the  operator 
can  substitute  a good  feeder  for  the 
faulty  one,  cut  off  the  defective 
feeder,  open  the  switch  of  the  arc- 
ing-ground suppressor  and  the  sys- 
tem has  been  returned  to  its  nor- 
mal operation  without  even  a mo- 
mentary delay  to  any  substation. 

(This  assumes  that  the  insulation 
of  the  system  is  high  enough  to  stand  oper- 
ation with  one-phase  wire  grounded  for  a 
short  time.)  It  should  be  noted  that  while 
the  faulty-feeder  localizer  and  arcing  ground 
suppressor  form  an  ideal  combination  either 
device  may  be  operated  independently. 

The  localizer  consists  of  a set  of  inter- 
connected relays  (one  relay  for  each  feeder). 
These  relays  have  two  coils  each,  the  pulls 
of  each  coil  of  the  pair  are  balanced  against 
each  other,  and  the  only  relay  which  operates 
is  the  one  in  which  an  unbalancing  occurs. 
By  properly  connecting  up  the  relays,  they 
are  made  independent  of  all  load  current,  no 
matter  how  unbalanced.  A time-limit  device 
is  added  to  the  relay  to  make  it  independent 
of  momentary  surges.  These  two  parts  form 
i a unit  and  there  is  one  unit  for  each  feeder. 
The  relays  are  mounted  on  the  back  of  a panel. 


Faulty-Feeder  Localizer 


The  relays  are  operated  from  the  feeder 
current  transformers.  It  is  necessary  to  have 
a current  transformer  in  every  high-tension 
wire  of  every  cable  on  which  it  is  desired  to 
operate  the  localizers.  The  transformers 
in  a single  feeder  have  to  be  of  the  same  type 
and  ratio;  however,  it  is  not  necessary  for 
transformers  on  different  lines  to  be  similar. 
It  is  possible  to  use  either  the  meter  trans- 
formers or  the  overload  relay  transformers 
(provided  a complete  set  is  installed  on  each 
feeder)  without  interfering  with  either  of 
these  devices.  An  alternate  arrangement  is 
to  install  separate  current  transformers  for 
the  localizer. 

The  localizer  is  not  intended  to  prevent  a 
fault  developing  and  consequently,  will  not 
do  so.  It  only  indicates  the  defective  line 
after  the  fault  has  developed.  A.  H.  D. 


1230 


GENERAL  ELECTRIC  REVIEW 


QUESTION  AND  ANSWER  SECTION 

The  purpose  of  this  department  of  the  Review  is  two-fold. 

First,  it  enables  all  subscribers  to  avail  themselves  of  the  consulting  service  of  a highly  specialized 
corps  of  engineering  experts,  or  of  such  other  authority  as  the  problem  may  require.  This  service  provides 
for  answers  by  mail  with  as  little  delay  as  possible  of  such  questions  as  come  within  the  scope  of  the  Review. 

Second,  it  publishes  for  the  benefit  of  all  Review  readers  questions  and  answers  of  general  interest 
and  of  educational  value.  When  the  original  question  deals  with  only  one  phase  of  an  interesting  subject, 
the  editor  may  feel  warranted  in  discussing  allied  questions  so  as  to  provide  a more  complete  treatment 
of  the  whole  subject. 

To  avoid  the  possibility  of  an  incorrect  or  incomplete  answer,  the  querist  should  be  particularly  careful  to 
include  sufficient  data  to  permit  of  an  intelligent  understanding  of  the  situation.  Address  letters  of  inquiry  to 
the  Editor,  Question  and  Answer  Section,  General  Electric  Review,  Schenectady,  New  York. 


Announcement 

In  the  1914  Annual  Index  of  the  General 
Electric  Review,  included  in  this  issue,  there 
appears  a complete  classified  index  of  the  Question 
and  Answer  material  for  this  year.  It  is  recom- 
mended that  this  index  be  kept  at  hand  in  order 
that  the  greatest  service  to  be  derived  from  the 
solutions  of  past  problems  may  be  conveniently 
available. — Editor. 

TRANSFORMER:  EXPLOSION 

(122)  What  is  the  initial  cause  that  later  results 
in  an  oil-cooled  transformer  blowing-up  or 
exploding? 

What  is  the  action  following  the  primary 
cause  that  actually  produces  the  explosive  effect? 

What  attention  is  given  in  the  construction 
of  standard  transformers  to  the  prevention  of 
explosions? 

The  condition  which  renders  favorable  the  possi- 
bility of  an  explosion  within  the  tank  of  an  oil-cooled 
transformer  is  that  of  an  accumulation  of  hydro- 
carbon gases  and  hydrogen  mixed  with  air  between 
the  surface  of  the  oil  and  the  transformer  cover. 
Providedno  ventis  supplied  whereby  the  inflammable 
gases  may  escape  from  the  case,  an  accumulation 
of  them  may  result  from  an  electric  arc  or  succession 
of  arcs  beneath  the  oil  surface. 

Although  confined,  no  inflammable  mixture  of 
gases  and  air  will  explode  unless  raised  to  its  flash 
temperature  by  a flame,  spark,  etc.  Where  explo- 
sions have  occurred,  the  ignition  may  be  attributed 
to  an  arc,  or  to  corona  on  the  conductors  or  leads, 
above  the  oil  surface. 

Since  it  is  far  preferable  to  avoid  the  possibility 
of  having  an  explosion  occur  and  since  it  has  been 
found  impracticable  to  design  a tank  to  resist  a 
severe  explosion  should  it  take  place,  standard 
transformers  are  equipped  with  “breathers”  or 
gas  vents  which,  besides  minimizing  the  con- 
densation of  moisture,  permit  the  escape  of  the 
generated  gases  fast  enough  to  prevent  the  pro- 
duction of  a highly-explosive  mixture. 

R.  K.  W. 

CATENARY  TROLLEY  CONSTRUCTION: 
STRESS  FORMULAE 

(123)  Will  you  please  publish  or  furnish  references 
to  a set  of  formulae  from  which  the  stress  occur- 
ring in  the  messenger  cable  and  in  the  trolley 
wire,  as  used  in  catenary  construction,  may  be 
obtained.  It  is  desired  that  they  apply  to  a line 
having  hangers  about  10  ft.  apart  and  spans 
varying  from  90  to  150  ft.,  and  that  they  take 
into  account  variations  of  temperature  from 
— 20  deg.  to  -|-120  deg.  F.  and  at  least  an  8-lb. 


wind  and  a inch  ice  load,  also  combinations  of 
these  conditions. 

As  far  as  we  know,  no  set  of  formulae  has  been 
arranged  that  will  give  exact  results  when  applied 
to  catenary  trolley  construction.  Since  the  mes- 
senger cable  has  approximately  uniform  loading 
only  at  normal  temperature,  ordinary  transmission 
line  formulae  are  not  strictly  correct.  They  are, 
however,  often  used  where  actual  test  measure- 
ments are  not  at  hand.  Useful  formulae  have  been 
published  at  various  times  of  which  consideration 
may  be  given  to  the  following: 

Proceedings  A.S.C.E.,  June,  1908 — Mr.  R.  D. 
Combs. 

Elect.  Rwy.  Journal,  October,  1908 — Mr.  R.  L. 
Allen. 

Overhead  Electric  Power  Transmission,  Mr.  Alfred 
Still. 

Handbook  on  Overhead  Line  Construction — N.E. 
L.A.  C.J.H. 

TURBINES:  RELIEF  VALVES  LOW-PRESSURE  END 

(124)  What  is  the  reason  for  not  installing  relief 
valves  on  the  low-pressure  end  of  Curtis  turbines? 

Any  small  valve  which  could  be  provided  on 
the  shell  of  a large  turbine  to  allow  for  a discharge 
into  the  station  could  only  be  considered  as  a 
signal  or  alarm,  for  it  would  not  be  practicable  to 
place  in  such  a position  on  the  machine  a valve 
that  would  be  sufficiently  large  to  be  of  any  material 
benefit  in  preventing  excessive  pressure  in  the  shell. 
In  fact,  any  small  relief  valve  placed  on  a large 
turbine  is  more  liable  to  prove  to  be  a source  of 
danger  than  to  be  one  of  benefit,  for  the  reason 
that  the  station  operators  might  consider  this  valve 
would  prove  to  some  extent  a safeguard  in  operation 
which,  of  course,  it  could  not. 

The  larger  the  turbine  the  greater  the  degree  to 
which  this  statement  holds  true.  Operating  engi- 
neers, realizing  this,  arrange  to  install  an  atmos- 
pheric relief  valve  on  the  condenser  or  on  a con- 
nection between  the  turbine  and  the  condenser. 
This  valve  is  made  to  have  sufficient  capacity  to 
prevent  an  excessive  pressure  being  built  up  in  the 
shell  should  the  condenser  fail  at  any  time. 

In  the  case  of  small  turbines  it  would  be  practi- 
cable, of  course,  to  place  a relief  valve  of  ample 
dimensions  on  the  machine.  However,  it  has  been 
commonly  experienced  that  in  practically  every 
case  the  operator  prefers  an  atmospheric  relief 
valve  that  can  be  piped  up  to  discharge  out  of  doors; 
and,  consequently,  since  it  seems  best,  the  uniform 
practice  of  not  installing  low-pressure  relief  valves 
on  all  size  Curtis  turbines  has  been  adopted. 

E.D.D. 


GENERAL  ELECTRIC  REVIEW 


XIII 


Sales  Offices 

of  the  General  Electric  Company 

This  page  is  prepared  for  the  ready  reference  of  the  readers  of  the  General  Elec- 
tric Review.  To  insure  correspondence  against  avoidable  delay,  all  communica- 
tions to  the  Company  should  be  addressed  to  the  sales  office  nearest  the  writer. 


Atlanta,  Ga.,  Third  National  Bank  Building 
Baltimore,  Md.,  Munsey  Building 
Birmingham,  Ala,,  Brown-Marx  Building 
Boston,  Mass,,  84  State  Street 
Buffalo,  N,  Y,,  Electric  Building 
Butte,  Montana,  Electric  Building 

Charleston,  W,  Va,,  Charleston  National  Bank  Building 

Charlotte,  N.  C,,  Commercial  National  Bank  Building 

Chattanooga,  Tenn,,  James  Building 

Chicago,  III,,  Monadnock  Building 

Cincinnati,  Ohio,  Provident  Bank  Building 

Cleveland,  Ohio,  Illuminating  Building 

Columbus,  Ohio,  Columbus  Savings  & Trust  Building 

Dayton,  Ohio,  Schwind  Building 

Denver,  Colo.,  First  National  Bank  Building 

Des  Moines,  Iowa,  Hippee  Building 

Detroit,  Mich.,  Dime  Savings  Bank  Bldg.  (Office  of  Agent) 

Duluth,  Minn.,  Fidelity  Building 

Elmira,  N.  Y..  Hulett  Building 

Erie,  Pa.,  Marine  National  Bank  Building 

Fort  Wayne,  Ind.,  Fort  Wayne  Electric  Works 

Indianapolis,  Ind.,  Traction  Terminal  Building 

Jacksonville,  Fla.,  Heard  National  Bank  Building 

Joplin,  Mo.,  Miners’  Bank  Building 

Kansas  City,  Mo.,  Dwight  Building 

Knoxville,  Tenn.,  Bank  & Trust  Building 

Los  Angeles,  Cal.,  124  West  Fourth  Street 

Louisville,  Ky.,  Starks  Building 

Memphis,  Tenn.,  Randolph  Building 

Milwaukee,  Wis.,  Public  Service  Building 

Minneapolis,  Minn.,  410  Third  Ave.,  North 

Nashville,  Tenn.,  Stahlman  Building 

New  Haven,  Conn.,  Second  National  Bank  Building 

New  Orleans,  La.,  Maison-Blanche  Building 

New  York,  N.  Y.,  Hudson  Terminal  Building 


Niagara  Falls,  N.  Y.,  Gluck  Building 

Omaha,  Neb.,  Union  Pacific  Building 

Philadelphia,  Pa.,  Witherspoon  Building 

Pittsburg,  Pa.,  Oliver  Building 

Portland,  Ore.,  Electric  Building 

Providence,  R.  I.,  1012  Turks  Head  Building 

Richmond,  Va.,  Virginia  Railway  and  Power  Building 

Rochester,  N.  Y.,  Granite  Building 

Salt  Lake  City,  Utah,  Newhouse  Building 

San  Francisco,  C.\l.,  Rialto  Building 

Schenectady,  N.  Y.,  G-E  Works 

Seattle,  Wash.,  Colman  Building 

Spokane,  Wash.,  Paulsen  Building 

Springfield,  Mass.,  Massachusetts  Mutual  Building 

St.  Louis,  Mo.,  Pierce  Building 

Syracuse,  N.  Y.,  Onondaga  County  Savings  Bank  Bldg. 
Toledo,  Ohio,  Spitzer  Building 
Washington,  D.  C.,  Evans  Building 
Youngstown,  Ohio,  Wick  Building 


For  Texas,  Oklahoma  and  Arizona  business  refer  to  South- 
west General  Electric  Company  (formerly  Hobson 
Electric  Co.) 

Dallas,  Texas,  1701  No.  Market  Street 
Houston,  Texas,  Third  and  Washington  Streets 
El  Paso,  Texas,  500  San  Francisco  Street 
Oklahoma  City,  Okla.,  Insurance  Building 
For  Hawaiian  business  address 

Catton  Neill  & Company,  Ltd.,  Honolulu 
For  all  Canadian  business  refer  to 

Canadian  General  Electric  Company,  Ltd.,  Toronto. 
Ont. 

For  business  in  Great  Britain  refer  to 

British  Tiiomson-Houston  Company,  Ltd.,  Rugby, 
England 


FOREIGN  OFFICES  OR  REPRESENTATIVES: 

Argentina:  Cia.  General  Electric  Sudamericana,  Inc.,  Buenos  Aires;  Australia:  Australian  General  Electric  Co.,  Sydney  and 
Melbourne;  Brazil:  Companhia  General  Electric  do  Brazil,  Rio  de  Janeiro;  Central  America:  G.  Amsinck  & Co.,  New  York, 
U.  S.  A.;  Chile:  International  Machinery  Co.,  Santiago,  and  Nitrate  Agencies,  Ltd.,  Iquique;  China:  Andersen,  Meyer  & 
Co.,  Shanghai;  Colombia:  Wesselhoeft  & Wisner,  Barranquilla;  Cuba:  Zaldo  & Martinez,  Havana;  England:  General 
Electric  Co.  (of  New  York),  London;  India:  General  Electric  Co.  (of  New  York),  Calcutta;  Japan  and  Korea:  General 
Electric  Co.  and  Bagnall  & Hilles,  Yokohama;  Mitsui  Bussan  Kaisha,  Ltd.,  Tokyo  and  Seoul;  Mexico:  Mexican  General 
Electric  Co.,  Mexico  City;  New  Zealand:  The  National  Electrical  & Engineering  Co.,  Ltd.,  Wellington,  Christchurch,  Dune- 
din and  Auckland;  Peru:  W.  R.  Grace  & Co.,  Lima;  Philippine  Islands:  Frank  L.  Strong  Machinery  Co..  Manila;  South 
Africa:  South  African  General  Electric  Co.,  Johannesburg,  Capetown  and  Durban. 


General  Electric  Company 

General  Office:  Schenectady,  N.  Y. 

Member  of  the  Society  for  Electrical  Development,  Inc. 

“DO  IT  ELECTRICALLY” 


XIV 


GENERAL  ELECTRIC  REVIEW 


T 

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k 

i 

r ^ 

1 

u 

Preserve  Your  Copies 
of 

GENERAL 

ELECTRIC 

REVIEW 


Let  us  do  your  binding, 

BINDING  I 

Black  Half  Morocco  Leather. $2.00 

Maroon  Heavy  Buckram $1.00 

BOUND  VOLUMES  (1913,  1914) 

Black  Half  Morocco  Leather.,... $4.00 

Prices  include  carrier's  charges  one  way. 

Forward  your  copies  by  mail  or  express  (prepaid)  and 
remit  by  money  order  or  check. 


GENERAL  ELECTRIC 
REVIEW 


SCHENECTADY,  N.  Y. 


GENERAL  ELECTRIC  REVIEW 


XV 


w 


All  Silent  Chains  Look  Alike 

But  there  is  none  possessing  the 
Liner  Type  Joint  of 

Link-Belt  Silent  Chain 


* 't  ’HE  SUCCESS  of  the  Link-Belt  Silent  Chain  is  due  almost  entirely  to 
^ the  superiority  of  its  joint  construction.  The  segmental  liners  or  bush- 
ings, which  are  removable,  extend  across  the  entire  width  of  the  chain, 
thus  doubling  the  bearing  surface  and  halving  the  bearing  pressure  on 
the  joint.  The  bushings  (or  liners)  are  case  hardened,  and  bear  upon  the 
case-hardened  pin.  The  latter  is  free  to,  and  does,  rotate  with  reference 
to  the  bushings  and  presents  every  particle  of  its  surface  for  wear.  As  a 
result  it  wears  uniformly,  keeps  round,  and  the  chain  maintains  to  the  end 
its  high  initial  efficiency,  (98.2%  on  actual  test). 

Write  for  Link-Belt  Silent  Chain  Data  Book  No.  125. 

LINK-BELT  COMPANY 


PHILADELPHIA 


CHICAGO 


INDIANAPOLIS 


New  York 299  Broadway 

Boston 49  Federal  Street 

Pittsburgh 1501-3  Park  Bldg. 

St.  Louis Central  Nat’l  Bank  Bldg. 

Buffalo 698  Ellicott  Square 

Detroit 911  Dime  Bank  Bldg. 

Cleveland Rockefeller  Building 


Montreal,  Can John  Millen  & Sons.  Ltd. 


Seattle 512i  First  Avenue  S. 

Denver Lindrooth,  Shubart  & Co. 

San  Francisco Meese  & Gottfried  Co. 

New  Orleans Whitney  Supply  Co. 

Birmingham General  Machinery  Co. 

Los  Angeles 204  N.  Los  Angeles  St. 

Minneapolis Link-Belt  Supply  Co. 


o, 


o 


'o. 


Average  Hours  per  day 


The  time  to  sell 
High  Efficiency 

EDISON  MAZDAS 


T^ECEMBER,  the  darkest  month,  is  also  the  busiest  month  of  the  year  for  re- 
tail  stores.  For  the  Holiday  trade,  stores  require  a great  abundance  of  light. 
To  attract  attention  to  window  displays  and  to  invite  people  inside,  the  store 
fronts  at  this  season  are  always  brilliantly  lighted. 

Here,  then,  is  a profitable  field  for  thousands  of  the  big,  powerful,  high-elfi- 
ciency,  gas-filled,  EDISON  MAZDA  Lamps,  not  only  for  exterior  lighting  but  also 
for  use  inside  the  store.  Send  out  your  salesmen  now  with  samples  to  call  at  all 
the  stores  in  town.  Advertise!  Circularize!  But  be  sure  that  your  own  store 
front  and  windows  are  evidence  that  you  practice  as  you  preach. 

Be  sure  that  the  name  EDISON  appears  on  the  lamps  you  sell — or  buy — 
their  wonderful  efficiency  and  unrivalled  reputation  make  them  quick  sellers. 
Remember  too  that  factories,  theatres,  armories,  churches,  dance  halls,  motion 
picture  houses,  hotels  and  many  other  places  offer  countless  opportunities  for 
“high-efficiency”  installations. 


LAMP  WORKS 


^Jhis  owiAm  m all 


OF  GENERAL  ELECTRIC  COMPANY 

General  Sales  OflSce.  Hairison.N.  J.  gges  Agencies  Eve^rwhere 


GENERAL  ELECTRIC  REVIEW 


XVII 


EDISON  DAY 
RESULTS 

p ARLY  returns  from  the  “front”  are  unanimous  in  report- 
ing remarkable  success  for  the  Edison  Day  campaign. 
It  is  by  far  too  early  even  to  estimate  on  the  total  results. 
But  this  we  know — that  the  progressive  lighting  companies 
and  agents  in  nearly  all  of  the  more  important  cities  and 
towns  of  the  United  States  have  co-operated  with  us  in  a 
way  sure  to  make  Edison  Day  an  anniversary  to  be  remem- 
bered. 

That  this  country-wide  campaign  has  greatly  stimu- 
lated the  sale  of  Edison  MAZDA  Lamps  is  now  evident. 
That  the  results  will  be  beneficial  is  clear. 


Just  how  long  this  campaign  will  be  felt  in  any  locality 
depends  largely  on  how  aggressively  it  is  followed  up  in 
that  locality.  All  those  who  ran  local  Edison  Day  cam- 
paigns showed  their  wisdom— and  a word  to  the  wise  is 
sufficient. 


^This  symbol  on  oU 
EdisonMtudoQiitKif 


EDISON  LAMP  WORKS 


OF  GENERAL  ELECTRIC  COMPANY 

General  Sales  Office.  Harrison.N. J.  Agencies  Eveiywhere 


c/DnUend 

^tCbodsEiedriar 


XVIII 


GENERAL  ELECTRIC  REVIEW 


The  Babcock  & 
Wilcox  Company 

85  Liberty  Street,  New  York 

Water  Tube 
Steam  Boilers 

Steam  Superheaters 
Mechanical  Stokers 

Works:  Barberton,  Ohio;  Bayonne,  N.  J. 


Built  like  a 
Battleship! 

The  foundation  and  “hull”  of  a Wabash  steel 
car  are  built  of  solid  steel-bolt-riveted  steel 
plates.  Ease  of  mind,  as  well  as  ease  of 
body,  is  provided  by  trains  via 

WABASH 

between  St.  Louis 
and  Kansas  City 

eight  fast  trains  daily  between  these  cities,  via 
Wabash. 

|^"FOm)WTHEnAG 

J.  D.  McNamara, 
General  Pas.enger  Agent 
St.  Loui.,  Mo. 


TOOLS  FOR  ELECTRICAL 
CONSTRUCTION  WORK 

We  make  a specialty  of  tools  used  in  electrical  construc- 
tion and  maintenance  work.  Communicate  with  us  for 
any  requirements  for  linemen,  construction  gangs,  signal 
men,  electricians  and  kindred  artisans.  Fifty  years’ 
association  with  the  manufacture  of  tools  has  made  us 
familiar  with  the  special  requirements.  We  manufacture 
the  “Klein  Line”  of  tools  and  sell  such  other  lines  as 
we  have  found  reliable  which  will  mesh  in  with  the 
products  of  our  own  manufacture  to  make  a complete 
layout  of  linemen’s,  electricians’  and  construction  tools. 

We  manufacture  in  our  own  factories;  Splicing 
Clamps,  Climbers,  Wire  Grips,  Lag  Screw 
Wrenches,  Wire  Twisters,  Pocket  Tool  Sets, 
Tree  Trimmers,  Tackle  Blocks,  Trolley  Wire 
Grips,  The  “Haven’s”  Wire  Grip,  “Chicago” 
Wire  Grip,  Reel  Jacks,  Wire  Reels,  Pike  Poles, 
Pole  Jinnies,  Steel  Digging  and  Tamping  Bars, 
Post  Hole  Augers,  Cant  Hooks,  Carrying 
Hooks,  Pliers,  etc.,  and  we  have  a large  stock  of 
miscellaneous  tools  always  on  hand. 

Catalogs  sent  on  request. 

MATHIAS  KLEIN  & SONS 

CANAL  STATION  71  - - - - CHICAGO 


INDIA  MICA 
& 

SPLITTINGS 

D.  JAROSLAW 

19  TOWER  HILL 
LONDON  ENGLAND 

Silk 

For  Electrical 
Purposes 

Silk  for  Insulat- 
ing Finest  Wire 

raiding  Silk 

.yle  & Co. 

NEW  YORK 
CITY 

All  Kinds  B 
William  R 

225  Fourth  Ave., 

Cor.  18th  St. 

GENERAL  ELECTRICtREVIEW 


XIX 


We  Finance  Extensions  and 
Improvements 

to  Electric  Light,  Power  and  Street  Railway  properties  which  have 
established  earnings.  If  prevented  from  improving  or  extending 
your  plant  because  no  more  bonds  can  be  issued  or  sold,  or  for  any 
other  reason,  correspond  with  us. 

Electric  Bond  and  Share  Company 

Paid-up  Capital  and  Surplus,  $12,500,000 

71  Broadway,  New  York 

Dealers  in  Proven  Electric  Light,  Power  and  Street  Railway  Bonds  and  Stocks 


BRASS,  BRONZE, 
COPPER  AND 

The  American 

EXTRUDED 

METAL 

GERMAN  SILVER 
Sheets,  Rolls,  Plates, 
Wire  and  Rods,Seam- 
less  and  Brazed 

Brass  Company 

Rods,  Special  Shapes 
and  Pressed  Metal 
Parts. 

Tubing.  Mouldings, 
Angles  and  Channels, 
Circles,  Blanks  and 
Shells. 

Manufacturers  of 

Brass,  Bronze,  Copper 

BARE  AND  INSU- 
LATED COPPER 
WIRE  AND  CABLE 
“K.K.”  Weather- 

TOBIN  BRONZE— 
PHOSPHOR 
BRONZE 

and  German  Silver 

Proof  and  Slow-Burn- 
ing Wire. 

Round  and  Flat 

Magnet  Wire,  Office 

Plates,  Wire,  Rods 
and  Seamless  Tubes. 

Mills  and  Factories 

and  Annunciator 
Wire. 

Ansonia  Brass  and  Copper  Branch, 

BENEDICT 

Ansonia,  Conn. 

DRAWN  COPPER 

NICKEL  WHITE 

Benedict  and  Burnham  Branch, 

FOR  ELECTRICAL 

METAL 

Waterbury,  Conn. 

PURPOSES 

Seamless  Tubing, 

Coe  Brass  Branch,  Torrington,  Conn. 

Rectangular  Bars  and 

Sheets,  Wire,  Rods 

Coe  Brass  Branch,  Ansonia,  Conn. 

Strips,  Commutator 

and  Ingots. 

Kenosha  Branch,  Kenosha,  Wls. 

Waterbury  Brass  Branch,  Waterbury,  Conn. 

Copper. 

XX 


GENERAL  ELECTRIC  REVIEW 


Pipe  and  Boiler  Coverings 

ASBESTOS  MATERIALS 
of  all  kinds 

SOLD  AND  APPLIED 

Production 

' is  possible  if  the  mechanic 

is  equipped  with 

Packings 

ASBESTOS,  RUBBER,  FLAX, 
STEAM,  WATER,  AMMONIA 
OIL 

Starrett  Tools 

These  tools  are  designed  to  serve  a variety 
of  purposes  and  are  made  so  that  they  stand 
years  of  service.  Is  your  factory  taking 
advantage  of  every  method  that  will  increase 
its  production? 

Stnd  for  Catalog  No.  20,  and  see  if  there  is 
not  something  in  it  which  you  should  have. 

Robert  A.  Keasbey  Co. 

100  No.  Moore  Street 
New  York 

EXPERT  ADVICE  ON  APPLICATION 

We  manufacture  Fine  Mechanical  Tools 
Bevels,  Calipers  and  Dividers,  Center  Te8ters,Clamps, 
Drill  Blocks,  Gauges,  Hack  Saws  and  Frames,  Levels, 
Micrometers,  Rules,  Scribers,  Speed  Indicators, 
Squares,  Test  Indicators,  Etc. 

The  L.  S.  Starrett  Co. 

WORLD’S  GREATEST  TOOL  MAKERS 

Athol,  Mass. 

42-161 

The  Gamewell  Fire  Alarm 
Telegraph  Company 


General  Offices  and  Works: 
NEWTON  UPPER  FALLS,  MASS. 

Fire  Alarm  and  Police  Telegraphs  for 
Municipal  and  Private  Plants. 

Over  1700  plants  in  actual  service. 


AGENCIES:  ' 

5708  Grand  Central  Terminal,  New  York  City. 

448  John  Hancock  Building,  Boston,  Mass. 

1216  Lytton  Building,  Chicago,  111. 

335  Wabash  Bldg.,  Pittsburg,  Pa. 

915  Postal  Bldg.,  San  Francisco,  Cal. 

304  Central  Bldg.,  Seattle,  Wash. 

Utica  Fire  Alarm  Tel.  Co.,  Utica,  N.  Y. 

The  Northern  Electric  & Mfg.  Co.,  Ltd.,  Montreal, 
Canada. 

General  Fire  Appliances  Co.,  Ltd.,  Johannesburg, 
South  Africa. 

Colonial  Trading  Co.,  Ancon,  Canal  Zone,  Panama. 

F.  P.  Danforth,  1060  Calle  Rioja,  Rosario  de  Santa  Fe, 
Argentina  Republic. 

Trajano  de  Medeiros  & Co.,  Rio  de  Janeiro,  Brazil. 

C.  Lorenz,  Berlin,  Germany. 


TAPES  and  WEBBINGS 

FOR  ELECTRICAL  WORK 


All  grades  and  qualities  required  in  the  build- 
ing and  repair  of  Dynamos,  Motors  and  other 
electrical  apparatus.  Every  detail  of  manufac- 
ture (quality  of  stock,  uniformity  of  width  and 
thickness,  etc.)  has  been  carefully  worked  out 
under  the  advice  of  the  best  electrical  engineers, 
and  special  machinery  constructed  to  produce 
material  as  nearly  perfect  as  possible. 

W Ttie  for  samples  and  prices. 


HOPE  WEBBING  CO. 

PROVIDENCE,  R.  I. 


GENERAL  ELECTRIC  REVIEW 


XXI 


Technical  Books 

WITH  SUBSCRIPTIONS  TO 

General  Electric  Review 

Every  engineer  should  own  a carefully  selected,  even  if  small,  shelf  of  up-to-date  books 
pertaining  to  the  work  in  which  he  is  engaged.  Through  an  arrangement  with  the  book  pub- 
lishers, we  are  enabled  to  offer  a year’s  subscription  to  the  Review  with  any  one  of  the  follow- 
ing books  at  a material  reduction  over  the  regular  price  for  the  two.  This  list  consists  almost 
entirely  of  the  more  recent  technical  publications;  full  description  of  the  older  works  will  be 
found  in  the  catalogues  of  the  publishers.  If  you  do  not  find  what  you  want  here,  write  us  about  it. 


(Amounts  in  parentheses  are  publisher’s  strictly  net  prices.)  combination 

PRICE 

Electric  Arcs,  by  C.  D.  Child.  Ph.  D.  ($2.00) $3.60 

Electric  Arc  Phenomena,  by  E.  Rasch  ($2.00) 3.60 

Transmission  Line  Formulas,  by  H.  B.  Dwight  ($2.00)  ............  3.60 

Single-Phase  Commutator  Motors,  by  F.  Greedy  ($2.00)  ...........  3.60 

Factory  Lighting,  by  Clarence  E.  Clewell  ($2.50)  .............  3.95 

High  Efficiency  Electrical  Illuminants  and  Illuminations,  by  W.  R.  Hutchinson  ($2.50)  ....  3.95 

Induction  Motors,  by  Benjamin  F.  Bailey  ($2.50) 3.95 

Electric  Traction  and  Transmission  Engineering,  by  Prof.  Sheldon  and  E.  Hausmann  ($2.50)  3.95 

The  Mathematics  of  Applied  Electricity,  by  Ernst  H.  Koch,  Jr.  ($3.00) 4.35 

Engineering  Mathematics,  by  Dr.  C.  P.  Steinmetz  ($3.00)  ...........  4.35 

Transmission  Line  Construction,  by  R.  A.  Lundquist  ($3.00) 4.35 

Overhead  Electric  Power  Transmission,  by  Alfred  Still  ($3.00) 4.35 

Thermodynamics  of  the  Steam  Turbine,  by  C.  H.  Peabody  ($3.00) 4.35 

Electric  Central  Station  Distribution  Systems,  by  H.  B.  Gear  and  P.  F.  Williams  ($3.00)  ....  4.35 

Synchronous  Motors  and  Converters,  by  Andrae  E.  Blondel  ($3.00) 4.35 

Electric  Railway  Engineering,  by  Francis  Harding  ($3.00) 4.35 

Electro-Thermal  Methods  of  Iron  and  Steel  Production,  by  J.  B.  C.  Kershaw  ($3.00)  ...  4.35 

High  and  Low  Tension  Switch  Gear,  by  A.  C.  Collis  ($3.50) 4.75 

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